Andrew Newbound © Andrew Newbound 2013. Universe Huge space which contains all of the mater and...

© Andrew Newbound 2013

Science Study Notes 2011

Andrew Newbound


Universe◦ Huge space which contains all of the mater and

energy in existence Big Bang

◦ Theory that universe started in a big explosion from a single point

Steady state◦ Theory that universe has always existed and matter

is being created all the time Cosmology

◦ Scientific study of theories about history & future of universe

Definitions


Evidence◦ Something that helps you form a conclusion

Organisms◦ Living things

Darwin◦ Created the theory of evolution and explained it

through the mechanism of natural selection Evolution

◦ Slow change in a population of living things over many generations

Definitions


Comparative anatomy◦ Study of similarities and differences in body

structures Fossils

◦ Remains/impressions of living things, mostly found in rock

Geographical Isolation◦ Natural arrangements of plants and animals in

particular regions Homo sapiens

◦ Scientific term form modern humans

Definitions


Lamarck◦ Suggested that evolution was caused by

organisms acquiring variations as they lived their lives, that were then inherited by their offspring.

Natural Selection◦ When only organism best adapted to their

environment will survive and transmit their genes to their offspring

Hominid◦ Early human-like fossils that walked upright on 2

legs and were more like humans than apes

Definitions


1929

• Edwin Hubble• Red Shift

1933

• Big Bang Theory

1948

• Steady state theory

The Big Bang


1965

• Robert Wilson & Arno ]]• Discovered microwave radiation in the

universe

1992

• COBE• (Cosmic Background Radiation

Explorer)

The Big Bang


Astronomer◦ Studies objects in space & info that can be derived

from them Cosmologist

◦ Studies theories about the universe Formation, history & future of universe

Astronomers & Cosmologists◦ Use telescopes + satellites + space probes◦ Computer simulations & models

Big Bang◦ Before = nothing◦ Started space, energy & time

The Big Bang


Origin of Universe Theory

For Against

Big Bang • Microwave energy detected from Big Bang (background radiation)

• Red shift (universe expanding)

• Ripples in universe

• Starting point

Steady state • Starting point explained

• Galaxies can’t be made of nothing

The Big Bang


Universe runs out of energy

Stops expanding

Universe shrinks

Back to size of Big Bang

The Big Crunch


1924

• Aleksanr Oparin• Life originated in pools of water

1953

• Stanley Miller• Showed how earth could have started• Wrong quantities of gases

• Fred Hoyle• Life originated in space• Molecules that make up life – on comets & dust of nebulae

The Beginnings of Life


1969

• September• Meteorite flashed across sky in Victoria

• 4600 million years old

1997

• ALH84001• Confirmed come from mars• Microscopic patterns similar to bacteria

colonies



Bacteria sent into space Spacecraft ‘STARDUST’ collected samples

from Comet Wild 2 in Jan 2004 Evidence for life on earth

◦ Fossils Oldest = bacteria

Use hydrogen sulphide as an energy source

Bacteria in harsh conditions◦ Archaea



Planetary scientists◦ Bacteria that can live in other places in the solar

system Mars

◦ Most probable planet to support life◦ Evidence for water has been detected

Best place to find bacterial life◦ Moon surrounding Jupitor/Saturn



Born: England 1809 Loved nature studies

◦ Large collection of beetles Sorted them

◦ Catalogued the varieties of pigeons Studied to be a doctor

◦ Left when witnessed a child in surgery Screaming with pain

Charles Darwin


Heard father & grandfather talk about evolution

Unpaid naturalist on voyage around world◦ Survey parts of world◦ Draw biological specimens + descriptions of them

South America◦ Large fossil bones of extinct animals

Resembled bones in living animals

Charles Darwin


After earthquake◦ Mussels moved to 3m above high tide mark◦ Showed environments change

Galapagos island finches◦ Each had different:

Shaped beak Source of food

◦ Similar to each other Like once same type of bird

Charles Darwin


Beetles◦ Small differences between living things are important

Pigeons◦ Living things change over time

Finches◦ Populations change over time and grow apart when

separated Findings

◦ Reluctant to publish◦ Alfred Russel Wallace had same findings◦ Darwin’s theory publicised & well known

Charles Darwin


Study of similarities & differences in body structures

Similarities◦ Determine evolutionary relationships

Limb adapted by evolution for use in different environments

Comparative Anatomy


Embryology◦ Study of embryos

All similar during early development

Comparative Embryology


Comparative anatomy◦ Some bones can be used for different purposes

Pentadacyl limb◦ Bones that are not used may still be around

Comparative embryology◦ Common ancestors changed to form different species◦ Split further along than embryos

Comparative DNA sequencing◦ Measuring how long ago 2 species were 1 species◦ Similarities compared

Humans & chimpanzees 5-6 million years ago (98% similar)

Evidence for Evolution


Fossils◦ Minerals replaced by carbonates◦ Impressions/casts◦ Chemicals can’t break down

Horse evolution using fossils◦ Come from N. America◦ Had 4 digits per limb◦ Changed to graze tough grasses◦ 3rd digit’s nail = hoof



Dating Fossils◦ Position in layers of rock

Law of superposition

◦ Potasium10 Argon40

Older fossils up to 1,000,000 years ago Measure amounts of argon

◦ Carbon14 dating Ratio of carbon14 to carbon12 50,000 years ago



Bio-Geographical Distribution◦ Ratites (flightless birds all related)

Emu, Kiwi etc.◦ Continental drift



All organisms contain chemicals that are based primarily on carbon

DNA Structural and chemical similarities between

things suggest relationships

Genetic sources


Study of fossils Evidence of evolution because oldest fossils

are simples animals & plants As rocks get younger the fossils get more

complex

Palaeontology


Australia has its own distinctive kinds of living things◦ E.g. waratah◦ Endemic to Australia

Explanations◦ Begin as inferences◦ Make hypothesis◦ Produce theories

Best scientific explanation at the time for the available evidence

Geographical Distribution of Related Species


Carbon Dating = Absolute Dating◦ 1000s of years ago

Relative dating◦ Only tell whether fossil is older or younger◦ Layer of rock found in

Dating Fossils


Artificial selection◦ Farmers selecting largest/strongest animals for

breeding Slight advantage

◦ More likely to survive◦ Natural selection

Slow◦ Many generations

E.g. Insect resistance to pesticides

Natural Selection


Use it or lose it Acquired characteristics WRONG

Lamarck's theory


Survival of the fittest All individuals have different characteristics

(variations) All individuals struggle to survive

◦ Find food, shelter and mates◦ Avoid danger

Some individuals born with variations help to survive◦ Survive best and reproduce to pass successful

variations onto offspring◦ Population changes so that it has characteristics that

make it best suited to the environment

Darwin’s Theory


Hominids◦ Closer to humans than apes

Pre-hominids◦ Closer to apes than humans

Humans different to other animals◦ Large brain for reasoning & language◦ Opposable thumb

Incomplete fossil records of human evolution

In The Beginning


Austalopithecus Homo habilis Homo erectus

NeanderthalsCro-Magnon manHomo Sapien

In the Beginning


Hominid fossil changes◦ Brains grew◦ Face became vertical◦ Brow ridges rose◦ Teeth shrunk

Neanderthals & Cro Magnons◦ Lived in caves

Shelter & protection Preserved from elements

Lots of fossils

Super species◦ Able to destroy all other living things on earth

In The Beginning


Gripped By Gravity (Motion)

Topic 2


Mass◦ The amount of matter in something

Weight◦ The force of gravity pulling on a mass

Force◦ A push, pull or twist applied to an object

Acceleration◦ The rate at which an object changes its speed

Net Force◦ The directional sum of all forces acting on an

object

Glossary


Friction◦ A rubbing force that slows moving objects

Distance◦ How far it is between 2 points

Speed◦ How quickly an object is moving

Time◦ How long it takes between 2 events

Average Speed◦ The total distance travelled divided by the total

time taken

Glossary


Velocity◦ Speed in a given direction

Ticker timer◦ A device that produces a series of dots on paper

Inertia◦ The tendency of an object to stay still or keep moving

Momentum◦ The product of mass and velocity

Newton’s laws◦ The 3 laws proposed by Sir Isaac Newton that

describe motion

Glossary


𝑆=𝐷𝑇

Speed Formula


Distance◦ Measured with tape measure/trundle wheel

Trundle wheel circumference = 1m Time

◦ Measured in seconds (s), minutes (min), hours (h), days and weeks Usually measured in s for experiments

Speed◦ In car, measured in km/h◦ In lab, measured in m/s (

Measuring Motion


Velocity◦ Important for ships at sea etc.

Instantaneous speed◦ Speed the moment you look at it◦ Measured: Speedometer, laser/radar speed gun

Average Speed◦ Speed if same speed constantly over journey

Average speed velocity, instantaneous velocity◦ Same as speed but with distance also

Measuring Motion


m/s km/h

Measuring Motion

×3.6

÷3.6


If go back to start, average velocity is 0

Velocity


Gradient tells speed◦ Steeper = faster◦ Flat = 0 (object not moving)◦ Straight line = speed not changing

Time along bottom Distance along side Scale must be constant

Distance/time Graphs


0 20 40 60 80 100 1200

50

100

150

200

250

300

350

400

450

500

Distance/time graph

Time (s)

Dis

tan

ce (

m)


Easier studied if broken down◦ Measure time taken to walk along segments of path

Constant speed = same distance in same time Ticker timer

◦ Measure time and distance together◦ Hits carbon paper at regular intervals◦ Dots close together = slow speed◦ Dots consistently spaced = consistent speed◦ Moving apart = accelerating◦ Need to know distance & time between dots

Time = 0.02s (◦ 1 dimension (forward & backward)

Measuring Speed


Use video camera◦ Use pause button on VCR to analyse motion

If picture contains ruler + clock Flashing light

◦ Disco – motion appears jerky Photographed = multiple images of moving dancers

◦ Stroboscopic light Flashes at regular intervals Multiple images of moving object

Multiflash photography Movement in 2 dimensions (up & down, left & right)

Measuring Speed


Distance from start to finish = cm= m

Number of gaps between dots = number of dots = s Speed = = /

= m/s

Calculating Speed Using Ticker Tape


Distance from start to finish =9.5 cm=0.095m

Number of gaps between dots =7 number of dots =0.14s Speed = =0.095/0.14

=0.68m/s

Calculating Speed Using Ticker Tape


Vertical axis = distance Horizontal axis = time Straight line sloping upwards

◦ Motion at a constant speed Horizontal dine

◦ Stationary object w/ no motion Zero speed At rest

Curved line sloping upwards◦ Acceleration

Distance – Time Graphs


Acceleration


If a car can go from 0km/h to 60km/h in 6s, what is its acceleration?

Acceleration


Shows acceleration◦ Slope of graph

Horizontal = constant speed Down = decelerating Up = accelerating

Speed/Time Graphs


0 120 240 3600

2

4

6

8

10

12

14

16

18

20

Speed/time Graph

Time (s)

Sp

eed

(m

/s)


Gravity & Acceleration Acceleration

◦ Change in motion over time Circular motion

◦ Changing direction but not speed◦ Still accelerated

Acceleration◦ Increase in speed

Deceleration◦ Decrease in speed


Jump from aeroplane◦ Keep accelerating until hit terminal velocity

Due to air resistance Car stopping at traffic lights

◦ Decelerates until hits 0 speed Satellite orbiting earth

◦ Constant speed but accelerating due to change in direction

Weightlessness◦ No gravity

E.g. being in space

Gravity & Acceleration


Jumping = better on moon Running = better on earth Acceleration =

◦ OR

Gravity & Acceleration


Speed◦ How fast something is moving

Acceleration◦ Going faster, slower or changing direction

Data◦ Information in numerical form

Graph◦ Visual way of displaying data

Ticker timer◦ Leaves dot on a paper tape to record motion

Chapter Review


Velocity◦ Speed in a given direction

Circular Motion◦ Motion of an object round and round

Harmonic◦ Motion of an object going to and fro

Pendulum◦ Swinging object that can be used to measure time

Weight◦ Downwards force due to gravitational acceleration

Chapter Review


Gravity affects objects at the same rate◦ Heavy stone, light stone fall at same time

Moon’s gravity < earth’s gravity◦ Can jump higher

Gravity causes objects to accelerate towards earth

Air resistance slows falling objects near earth◦ Terminal velocity

Constant speed◦ Same time to travel same distance

Chapter Review


Gravity is constant with/without air◦ Objects would fall faster due to no terminal

velocity Higher speed

◦ Shorter time to travel same distance Fall faster & faster if jump from plane

◦ Until hit terminal velocity Average speed

Chapter Review


Closer together = slower speed

Farther apart = faster speed

Moving apart = accelerating

Moving together = decelerating

Ticker Timer


Force◦ Push/pull/twist◦ Can change motion, shape of an object◦ Measured in Newtons (N)

Contact force◦ Push/pull/twist through touching an object◦ E.g. hammering a nail, lifting a book

Weight force◦ Movement caused by gravity

Pushes, Pulls and Twists


Reaction force◦ Pushes against your force◦ Stops you from crashing through the floor

Friction◦ Force that slows movement◦ Pushes against moving objects◦ Ice = low friction surface◦ Need to ride bike

Pushes, Pulls and Twists


Mass◦ Amount of matter inside an object◦ Measured in kg

Weight◦ Downwards force◦ Depends on your body’s mass + strength of gravity◦ Measured in Newtons (N)

Lift accelerates upward◦ Floor pushes upwards◦ Feet push harder against floor◦ Extra weight

Mass and Weight


Weightlessness◦ Occurs when there is no gravity

Neutron star = 10 million x mass

Mass and Weight


Vector◦ Arrow used to draw force◦ Longer = more force

Drawing Forces


Upwards push of

road

Thrust

Weight

Resistance

forces

1. Law of Inertia


Newton’s First Law of Motion states that an object will remain at rest, or will not change its speed or direction, unless it is acted upon by an outside, unbalanced force.

Constant speed = balanced forces Seatbelt

◦ Keeps passenger moving with vehicle◦ Prevents law of ineria

1. Law of Inertia


Newton's Second Law of Motion describes how the mass of an object affects the way that it moves when acted upon by one or more forces.

Larger objects accelerate less rapidly than smaller object acted upon with the same force.

Inertia◦ Property of object that makes them resist change

2.


Rocket accelerates◦ Loses mass yet has same force

◦ Acceleration is proportionate to force More mass = more inertia

2.


Net force◦ Sum of forces acting upon it◦ Taking into account their direction

Same side + Different –

Net Force; Resultant Force


‘For every action there is an equal and opposite reaction.’

OR ‘If one object pushes on another object, then the other object pushes back with equal force.’

Stand on floor◦ Weight force (downwards)=upward force of floor

action reaction Unbalanced

◦ Move in dirrection

Action/Reaction


Slippery floor◦ Move foot, lower force reaction ∴ slip

Moving in space◦ Cylinders of compressed gas attached to space

suits

Action Reaction


More momentum = harder to stop

Momentum


Reducing number of accidents Reducing injuries Seatbelts

◦ Hold occupants in their seas◦ Absorb inertia

Headrest◦ Reduce whiplash from inertia

Crumple zone◦ Crumples to absorb energy

Car Safety


Air bags◦ Absorb inertia & deceleration forces of occupants

Anti-lock brake systems (ABS)◦ Stop wheels from skidding

Friction lost with road Deep tread

◦ Maximum friction Twice as fast = 4 times longer to stop

Car Safety


Reaction time◦ Time taken for driver to react to danger◦ Moving from accelerator to the brake

Reaction distance◦ Distance car travels during reaction time

Braking distance◦ Distance taken for car to stop when brakes are

applied Stopping distance

◦ Total distance

Car Safety


Alcohol & fatigue ◦ Lower concentration◦ Increase reaction

time◦ Stop. Revive.

Survive.

Law 1◦ Seatbelts◦ Headrests

Law 2◦ Airbags◦ Crumple zones

Law 3◦ ABS◦ Tire tread

Car Safety


2 cars crash at 80km/h◦ = single car crashing into solid barrier

3x speed = 9x stopping distance 4x speed = 16x stopping distance 50km/h accident

◦ Dropped from a 3 storey building 100km/h accident

◦ Dropped from a 12 storey building

Physics Crash Video


Getting Into GenesTopic 3


Alleles◦ The alternative forms of each gene

Chromosome◦ A length of DNA, containing many genes

Dominant◦ The one of a pair of opposite characters that

appears when both are inherited Gametes

◦ The sex cells – sperm and ova

Glossary


Genetics◦ The study of inheritance and variation and the

factors controlling them Genotype

◦ The genetic make-up of an individual Heredity

◦ Passing on characteristics from one generation to the next

Heterozygous◦ Different alleles for a gene

Glossary


Homozygous◦ 2 of the same alleles for a gene

Meiosis◦ Cell division resulting in daughter cells with half

the chromosome number of the parent cell. (makes the sex cells)

Mendel◦ An Austrian monk who carried out experiments on

pea plants◦ ‘The father of genetics

Glossary


Mitosis◦ Cell division resulting in in 2 daughter cells each an exact

copy of the parent cell Mutation

◦ Results when a mistake is made in copying of DNA Phenotype

◦ How living things appear and function Recessive

◦ Appearing in offspring only when not masked by a dominant characteristic

Zygote◦ The 1st cell of a new individual, formed when a sperm

fuses with the ova during fertilisation

Glossary


All living things made of cells/product of cells◦ Cell theory

Unicellular◦ Only have 1 cell◦ E.g. bacteria

Multicellular◦ All familiar plants & animals

Cells & Organisms


Functions

• Take in substances (assimilate)

• Extract energy from food• Excrete their wastes• Grow• Reproduce• Respond to things

Parts

• Nucleus• Control centre

• Cell membrane• Controls what gets

in/out• Cytoplasm

• Liquid containing various structures (organelles)

Cells


Additions

• Chloroplasts• Make food

• Cell wall• Strengthens structure

• Vacuoles• Store water & dissolved substances

• Smaller/none in animal cells

Plant Cells


Cells Tissues OrgansBody

systems

Body System Structure


All cells = same size◦ Just diff quantity

Cells need body systems◦ Need food, water & oxygen

Delivered by body systems

Cells to Systems


Plant Cell

cytoplasm


Microscope


Eyepiece lens◦ Bends the light to make the object look bigger

Microscope tube◦ Light travels through it to the eyepiece

Coarse focus & fine focus knobs◦ Moves the lens up/down so that the object can be

seen clearly Objective lens

◦ Can be changed so that the object can be magnified more or less

Microscope


Stage◦ Holds the slide with the object you are looking at

in place Mirror

◦ Makes light bounce through the slide into the lens Base

◦ Holds the microscope up

Microscope


Cell tissue e.g.◦ Muscle, nerve, skin

Multi-cellular◦ Large groups of cells which specialise

Cell membrane◦ Outside of cell

Cytoplasm◦ Liquid inside cell◦ All except nucleus◦ Semi-transparent◦ Includes cytosol, various organelles

The Cell – How it Works


Organelles◦ Nucleus = most prominent◦ Mitochondria◦ Cytoskeleton◦ Ribosomes◦ Golgi complex◦ Lysomes

Nucleus◦ Contains DNA & runs the cell

The Cell – How it Works


Animal

Muscle cell

Muscle

Artery

Circulatory System

Horse

Plant

Epidermal cell

Epidermis

Leaf

Photosynthesis system (leaves & stem)

Whole plant

Cellular Organisation


Cannot function without food & water Correct temperature

◦ <0°C = cell stops functioning Water freezes

Respiration◦ Burning of food w/ oxygen = energy

What Cells Need to Survive


Energy is needed for◦ Growth◦ Reproduction◦ Other functions

What Cells Need to Survive


Nucleus◦ Contains DNA◦ Control centre of cell

Nuclear membrane◦ Surrounds the nucleus◦ Lets in and out RNA

Chemical copy of DNA Used to make protein

Cell membrane◦ Controls entry and exit of chemicals

Cell Organelles


Protoplasm◦ All contents of cell

Cytoplasm◦ All contents of cell except nucleus

Mitochondria◦ Produces energy from food

Ribosomes◦ Manufactures protein

Endoplasmic reticulum◦ Moves products through the membrane

Cell Organelles


Chloroplasts◦ Contains chlorophyll

Used for photosynthesis Lysosomes

◦ Stores enzymes Microfilaments/cytoskeleton

◦ Holds organelles in place Vacuoles

◦ Stores food & minerals

Cell Organelles


Nucleic acids◦ DNA

Deoxyribonucleic acid Stores coded instructions Double helix

Watson and Crick

◦ RNA Ribonucleic acid Allows DNA to read coded instructions

◦ Generally located in nucleus Prokaryote

It is located in an area of the cell Not in a membrane

Nuclear Matter


Nucleus◦ Control centre

Nucleus=programmed by DNA◦ Instructions

For making all parts of cell Way cell behaves

How carry out functions Transmitting Nerve impulse Supplying energy Contracting (muscle cells) Carrying out photosynthesis

Nuclear Matter


Nuclear membrane’s pores◦ Connect with endoplasmic reticulum◦ Transport material in and out of nucleus

Nucleus need to be stained to be visible under a microscope

Nuclear Matter


Shorted and coiled forms of DNA made when the cell is about the divide

Only visible when stained Human cell

◦ 23 pairs◦ 46 individual◦ Sex chromosomes

Information for sexual characteristics◦ Autosomes

Non-sex chromosomes

Nuclear Matter - Chromosomes


Process of sorting chromosomes into their matched pairs

Important in investigating chromosomal disorders

Karyotyping


Mitosis

1. Parent cell◦ Chromosomes appear as long thin threads

2. Chromosomes duplicate (chromatid pairs)◦ Become shorter and thicker

3. Chromatid pairs line up◦ Along the equator of the cell

4. Chromatids separate◦ Move to opposite ends of cell◦ Starts to split into 2 cells

5. Daughter cells◦ Chromosomes become longer, thinner and less

distinct


Homologous Pair◦ Chromosomes exist in pairs in each body cell. One

pair from the mother, one pair from the father Diploid

◦ 2 of each type of chromosome Haploid

◦ Genetes (ova/sperm) contain only 1 of each type of chromosome

Daughter cell◦ Cell that is an exact copy of parent cell due to

MITOSIS

Mitosis


Occurs in all body parts except sex cells Multicellular organism purpose

◦ Growth and repair Single-celled organism purpose

◦ Reproduction

Mitosis


Very complex form of cell division Begins same as mitosis Occurs only in reproductive organisms

◦ Ovaries & testes in humans After duplication of chromosomes

◦ From “half-cells” ½ of correct number of chromosomes for organism

Fertilisation◦ Recombine to give correct no. of chromosomes

Meiosis


Ova23

Sperm23

Zygote

Meiosis


1. 2 pairs of chromosomes are visible2. Chromosomes double

◦ Joined at centromere

3. Homologous pairs line up along equator4. One of each pair moves to ends of cell5. Chromosomes line up along equator6. Chromosomes separate

+ move to ends of cell7. Membranes form to produce 4 daughter

cells

Meiosis


Made of many nucleotides◦ Joined like links in a chain◦ Made of sugar – deoxyribose + phosphoric acid

+ nitrogenous base 4 bases

◦ Adenine◦ Thymine◦ Guanine◦ Cytosine◦ Order determines chemical code

Building DNA


Copied◦ Unzips along bases

RNA◦ Like DNA◦ In every cell◦ Sugar = ribose◦ Base uracil instead of Thymine◦ Used to make copies of DNA

Genome◦ Sequence of bases in the DNA/RNA of a living thing◦ Human = 3100 million base pairs

Building DNA


Gene◦ Length of DNA◦ Sequence of bases

Code for 1 protein Chromosome

◦ Length of genes DNA

◦ Carries all instructions for cell to function◦ Copied onto carrier molecule

Messenger RNA M-RNA

How DNA Works


m-RNA◦ Moves out through nuclear membrane

Into cytoplasm of cell◦ At ribosomes

Translated into protein Cells differentiate

◦ As multicellular organisms grow◦ Specialise into different roles & tasks

Stem cells◦ Cells which aren’t specialised◦ Take on any task

How DNA Works


DNA◦ The material that genes are made of◦ Deoxyribonucleic acid

Gene◦ Coded instructions that control our development

& body function Chromosome

◦ Collections of genes◦ Wound in double helix◦ 23 from each parent

Biotechnology


Mutation◦ Changes in the code of genes

Biotechnology◦ The exploitation of biological processes for

industrial and other prospects Clone

◦ Any organism with identical genes to their parent organism

Biotechnology


Completely decode human blueprint Fund laps to map genes of humans

◦ Physical + gene maps Needs 15 years

◦ 3 billion bases in genome

Human Genome Project


Pros

• Prevent genetic conditions• Testing genes early

on

Cons

• Insurance companies could use info

• Introduction of new genes could make others worse

• Parents may not want to know their condition

Human Genome Project


Foods derived from genetically modified organisms

E.g. soybean, corn, canola & cotton seed oil

GM Food


Advantages

• Lower price• Reduces use of toxic

chemicals• Prevents wasted crops• Solve hunger• Grow foods in different

climates• Improve vitamin & mineral

content• Faster growth

Disadvantages

• Lasting effects on other species

• Natural immunity of insects to GM plant changes

• Ownership of food• Allergens

GM Food


1st mammal cloned from an adult cell◦ 5th July 1996

Produced 6 lambs 2003

◦ Experienced progressive lung disease + severe arthritis

◦ Euthanized Possible cause of short life

◦ Born at age of 6 years◦ Only had 6 left

Dolly – The Cloned Sheep


Eliminate famine Eliminate STIs Social discrepancy

◦ Only few able to achieve

Cloning


Born Feb 2 1958 Discovered in 1990

◦ Treatment of cultivating skins from patient= ineffective Requires 14-21 days

◦ Scaring likely to occur Burn wounds taking 21+ days to heal

◦ Scaring less likely to occur <10 days

Dr Fiona Wood AM


Skin sheets produced in 10 days◦ More could be done

Spray on skin◦ CellSpray◦ Aerosol delivery system◦ Apply cultivated skin to larger burn areas

Treat burns victims quicker◦ Noticeable during Bali Bombings

Dr Fiona Wood AM


DNA◦ Carries code for making proteins

Form our bodies Made from proteins/products made by proteins

◦ Makes 20 diff amino acids 3 bases code for each amino acid

+ start and stop RNA/m-RNA

◦ Opposite to code for DNA Complementary

Occurs during mitosis

Reading the Code


Genetic fingerprinting◦ Using someone’s DNA to establish their identity◦ Relies on enzymes

Break DNA into short lengths Separated by Chroma typing

◦ Uses: Forensic work Confirming pedigree of valuable animals Checking genetic diversity of endangered animals

Reading the Code


Figure thing


Spontaneous change in gene/chromosome◦ Alteration in related characteristic

Increased rate due to mutagens◦ Mutation-causing agents◦ E.g.

X-rays Gamma rays Ultraviolet light Range of chemicals including benzene

Responsible for genetic variation we see today

Mutations


Discovered + made detailed investigations of base principals of heredity◦ How traits are inherited

Used pea plants◦ Started w/ pure breeding

Hybrids◦ Plants produced by crossing contrasting breeding

plants

Gregor Mendel


Dominant characteristic◦ Strong form

Recessive characteristic◦ Weak characteristic

Genes◦ Small factors that controlled inheritance

Alles◦ Diff forms of a gene◦ E.g. purple and white colours in flowers

Gregor Mendel


Phenotype◦ Appearance of new offspring

Genotype◦ Combination of genes that determine a

phenotype

Gregor Mendel


P generation (Breeding Parents)

F1 generation(first filial generation)

F2 generation(2nd generation)

Gregor Mendel


S s

s Ss ss

s Ss ss

Punnett Square

Short hair hybrid dog (Ss) and long haired hybrid dog (ss) with long hair being recessive


Heterozygous◦ Different alles

Homozygous◦ Same alles

Heterozygous/Homozygous


23 pairs of chromosomes 100,000 diff genes Linked genes

◦ Lying near each other on the same chromosome Particular characteristic

◦ Determined by 1 dominant/recessive genes Incomplete dominance

◦ Halfway between 2 genes

Human Inheritance


Females◦ 22 normal pairs of chromosomes

+ XX pair of sex chromosomes Males

◦ 22 normal pairs of chromosomes+ XY pair of sex chromosomes

Sex Determination


X Y

X XX XY

X XX XY

Sex Determination

Genotype: XX : XY 50% : 50%

Phenotype: Female : Male


Sex linked◦ Genes found on the X and Y chromosome

Y chromosome only has a few genes compared to the X chromosome

Sex linked genetic diseases◦ Caused by defective genes on X chromosome and

occur more frequently in males than females E.g. colour blindness

Sex Determination


Females◦ Must contain 2, reate faulty genes to be colour

blind X`X`

◦ 1 faulty gene = carrier Dominant normal gene = proper vision

Males◦ Need only one faulty gene to be colourblind

X`Y

Colour Blindness


X` Y

X XX` XY

X XX` XY

Colour Blindness

Normal mother and a colour-blind father

Genotype XX`:XY

Phenotype Female MaleCarrier Normal


X` Y

X` XX` X`Y

X XX` XY

Colour Blindness

Normal mother and a colour-blind father

Genotype XX`:X`X`:XY:X`Y

Carrier Carrier: Colour blind: Normal: colour blind

Phenotype Female:Female:Male:Male


Chemical ChangesTopic 4


Chemistry◦ Scientific study of matter, its properties and its

interaction with other matter and energy Model

◦ A representation of something based on a set of assumptions, usually determined through experiments

Charge◦ The net effect of losing or gaining atoms

Spelling List


Atom◦ The smallest particle of an element

Element◦ A substance made up of only 1 part of an atom

Molecule◦ A group of atoms joined by bonds

Compound◦ A group of different atoms that are joined in a

fixed ratio

Spelling List


Periodic table◦ The arrangement of elements into a table of

groups and periods Electron shells

◦ The arrangement of electrons around the nucleus, based on energy levels

Chemical formula◦ A shorthand way of writing the name of an

element or compound

Spelling List


Word equation◦ Shows the changes that occur in a chemical

reaction using words Chemical reaction

◦ Interactions in which atoms exchange or share electrons forming new chemical compounds

Reactant◦ The chemical compounds that combine to start a

chemical reaction Products

◦ The chemical compounds that are produced during a chemical reaction

Spelling List


All Substances

Pure Substances

Element

Compound

Mixtures

Chemistry Revision


Element◦ Cannot be broken down into simpler substances◦ E.g. oxygen, argon and helium

Compound◦ Pure substance that can be broken down◦ E.g. sodium chloride◦ Combined elements

Molecule◦ Joined atoms

Chemistry Revision


Element◦ Not made of anything except self◦ 92 in nature

Many too unstable Can’t look at atoms

◦ Too small◦ Everything we look with is made of atoms◦ Indirect evidence

How it affects what is around it

What are Atoms Made of?


Proton◦ Define the element◦ Positively charged◦ In nucleus

Neutron◦ No charge◦ Create diff isotopes of element

Electron◦ Negatively charged◦ Orbiting nucleus



Ion◦ Charged atom◦ Different number of protons to electrons

Isotype◦ Atoms of element with different number of

neutrons Nucleus

◦ Makes up 1/10,000 of space in atom Mostly empty space



Rutherford◦ Fired alpha particles at gold leaf

2 protons + 2 neutrons Positive charge

Expected to steer away & he would measure how much they changed direction Actually didn’t change direction very much Many came back at him



Niels Bohr◦ Electrons occupy own orbitals

Colours in emission spectra◦ Represent element giving off light◦ Represents energy level

Outer shell◦ Valance shell◦ Occupied by high energy electrons◦ Predicts properties & reactivity



The Periodic Table◦ Discovered by Mendeleev◦ Patterns appeared periodically◦ Gaps would be filled by elements

Predicted properties



Chemical symbol◦ Unique 1-3 letters◦ E.g. C=carbon, Cl=Chlorine

Atomic number◦ Number of protons in 1 atom of element

Atomic weight◦ Average weight of 1 atom of element◦ Different isotopes◦ Carbon = 12.0107



Group Number of electrons in outer shell (Valence electrons)

Alkali metals 1

Alkali Earth metals 2

Noble gases 8

Halogens 7



Period◦ Row of elements

Number of electrons in shell



Only 1 electron in outer shell

•Very reactive•Can be easily lost•Wants to lose•E.g. Lithium, sodium

Needs 1 electron in outer shell

•Strongly attracts elements to fill shell•E.g. Iodine, bromine, chlorine, fluorine



◦ Sodium donates 1 electron to chlorine Makes stable

◦ Compound Not mixture

Not similar properties to reactants



Ionic Bonding

•1 positive (cation) & 1 negative (anion)

Covalent Bonding

•Share electrons•Not as reactive



~ 400BC◦ Democritus

All substances consist of indestructible particles called atoms

1808◦ John Dalton

All matter consisted of atoms Could not be divided Same element = alike Combined in whole number ratios

Chemical Building Blocks


1897◦ Sir J.J Thomson◦ Plumb pudding

1911◦ Lord Rutherford

Nuclear model for atom 1913

◦ Niels Bohr Electrons orbit at different energy levels

1932◦ Sir James Chadwick

Discovered neutrons



Protons

• +• In

nucleus

Electrons

• -• Orbit

nucleus• of proton

Neutrons

• Neither +/-

• In nucleus

• About same size as proton



Mass number◦ No. of protons + neutrons

Looking into Atoms


Shows trends in properties between elements

Predict properties of elements Most elements are solids 2 elements are liquid at room temp (25º)

◦ Some melt just above 11 elements gases at room temp Heaviest natural = uranium

The Periodic Table


Electrons◦ Determine chemical properties of element◦ Orbit in layers/shells◦ Same number as protons◦ 2 fill 1st shell◦ 8 fill 2nd shell◦ 8 fill 3rd shell (1st 20 elements)◦ 4th shell = partly filled◦ Jump to higher energy level when heated

Electrons and Atoms


Electron configuration◦ E.g. aluminium = 2.8.3

Electrons and Atoms


Periodic table◦ Chart showing all elements in order of atomic

number Element

◦ Pure substances made of billions of same type of atom

Compound◦ Pure substance made of billions of same type of

molecule Symbol

◦ Short way of writing chemical name

Chemical Changes


Formula◦ Way of writing type & ratio of atoms in a compound

Molecule◦ Group of atoms joined in a fixed ratio

Electrolysis◦ Using electricity to cause a chemical change

Decomposition◦ Breakdown of compound into simpler substances

Proton◦ Part of nucleus of atom that determines identity of atom

Electron◦ Orbits nucleus of atom in energy shell

Chemical Changes


OPTIONAL CONTENT MAY GO

HERE


Chemical equation ◦ Shows more than word equation◦ Ratios and types of atoms present

Balanced equation◦ Shows even more◦ Atoms only change positions

Not created/destroyed Not shown in chemical equation

◦ Energy changes◦ Rate (speed) of reaction◦ How reactants change into products

Reading Equations


𝐴𝑐𝑖𝑑+𝑏𝑎𝑠𝑒→𝑠𝑎𝑙𝑡+𝑤𝑎𝑡𝑒𝑟Reactions With Acids


Salts◦ Ionic compounds

Hydrochloric acid◦ Chloride salts

Sulphuric acid◦ Sulphates

Reactions With Acids


𝑀𝑒𝑡𝑎𝑙+𝑎𝑐𝑖𝑑→ 𝑠𝑎𝑙𝑡+h𝑦𝑑𝑟𝑜𝑔𝑒𝑛Reactions With Acids


𝑀𝑒𝑡𝑎𝑙𝑜𝑥𝑖𝑑𝑒+𝑎𝑐𝑖𝑑→𝑠𝑎𝑙𝑡+𝑤𝑎𝑡𝑒𝑟Reactions With Acids


𝐴𝑐𝑖𝑑𝑠+𝐶𝑎𝑟𝑏𝑜𝑛𝑎𝑡𝑒𝑠→𝑆𝑎𝑙𝑡+𝑊𝑎𝑡𝑒𝑟 +𝐶𝑎𝑟𝑏𝑜𝑛𝐷𝑖𝑜𝑥𝑖𝑑𝑒Carbonates


Common acids◦ Hydrochloric◦ Sulphuric

Corrosive = harmful◦ Damage/eat away material it touches

Acids & Bases in the Home


Acid•Sour•Corrosive•Lose hydrogen in water

Base•Bitter•Slippery•Eat away proteins•Lose hydroxide in water



Indicator◦ Changes colour in different conditions

Acids & bases◦ Litmus

Red = acid Blue = base

◦ Water = neutral Neutralisation reaction

◦ Acid + base



Acids•Citric acid•Cola drinks•Milk•Shampoo

Bases•Laundry powder•Soap•Dishwashing detergent•Oven cleaners



Change of chemical partners Cloudy mixture formed

Precipitates


Soluble•Sodium salts•Potassium salts•Ammonium salts•Most sulfates•Calcium sulfate = slightly soluble

•Sodium carbonates•Potassium carbonate•Ammonium carbonate

Insoluble•Sulfates•Lead•Barium•Most carbonates

Precipitates


Ionic◦ Type of compound made from attraction of metal

and non-metal ions Covalent

◦ Type of compound made from two non-metals that share electrons

Ion◦ An atom that has lost or gained electrons and now

carries an electrical charge

Chemical Changes


Lattice◦ Large array of atoms or ions that repeats itself

millions of times Flame test

◦ Where the colours of the flame are used to identify the types of atoms present

Equation◦ A written record of the reactants and products in

a chemical reaction

Chemical Changes


Limewater◦ Reagent used to test for presence of carbon

dioxide Limestone

◦ Type of rock dissolved away by carbon dioxide gas dissolved in rainwater

Precipitate◦ An insoluble substance that forms when ions

come together Suspension

◦ An insoluble substance shaken in water

Chemical Changes


Element◦ A pure substance made of only one type of atom

Decomposition◦ When a group of atoms breaks apart into smaller

groups Neutralisation

◦ Reaction where an acid and a base react and destroy each other

Precipitate◦ An insoluble substance made from the reaction of

any two soluble substances

Chemical Changes


Covalent◦ Groups of compounds formed from atoms of

non-metals Ionic

◦ Groups of compounds formed from metal andnon-metal ions

Compound◦ A pure substance made of 2 or more different

atoms joined in a fixed ratio

Chemical Changes


Electron◦ The outermost part of an atoms that can be lost

or gained in chemical reactions Calcium carbonate

◦ The chemical compound present in lime, limestone, caves, chalk and cement

Flame test◦ Procedure where atoms are heated and the

colours they produce are recorded

Chemical Changes


Hydrochloric acid chloride salts Sulfuric acid sulfate salts Nitric acid nitrate salts Phosphoric acid phosphate salts

Chemical Changes


Combustion (burning)◦ E.g.

Corrosion◦ E.g.

Chemical Reactions


Acids + metals

◦ E.g.

Acids + carbonates

◦ E.g.

Chemical Reactions


Neutralisation◦ Acids are neutralised (cancelled) bases

pH 7 (neutral)

◦ E.g.

Chemical Reactions


Decomposition◦ Single compound is broken down/decomposed

Form 2 products◦ E.g.

Combination◦ 2 elements combining to form a single compound◦ E.g.

Chemical Reactions∆≡h𝑒𝑎𝑡


Oxygen◦ Glowing split will burst into flames in oxygen

Carbon dioxide◦ Burning splint is put out◦ Limewater turns milky

Hydrogen◦ Pop test

Chemical Reactions - Tests


Moisture◦ Often visible around top of a test tube when

heating a substance that contains water Nitrogen dioxide

◦ Brown-orange coloured gas

Chemical Reactions


Waves & EnergyTopic 5


Waves & radiation◦ Carries energy◦ Formed when particles are pushed from

normal/rest position Springs back to where they were

Pushes on near particles

Sound waves◦ Longitudinal wave motion

Move to and fro in the same & opposite direction to the wave

Move in direction of wave & return to original position Energy is pushed

Waves & Energy


Compressions◦ Particles move closer together

Rarefactions◦ Spread further apart

Longitudinal waves e.g.◦ Sound waves◦ Explosions◦ Some earthquake waves

Force of explosion◦ Pushes air away

Transferred energy Strong enough to break windows

Waves & Energy


Water waves◦ Ripples travel outwards◦ Transverse waves

At right angles Transverse waves

◦ Boat over water◦ E.g.

Water Pulse in spring Some earthquake waves

Waves & Energy


Progressive waves◦ Move energy from one place to another◦ Moving forwards◦ E.g. soundwaves

Standing waves◦ Identical waves in opposite directions◦ E.g. pulse in rubber tube

Travel through substance◦ E.g. water, sound

Don’t need substance to travel through◦ Electromagnetic

Light, radio

Waves & Energy


Waves & Energy

displacement


Waves & Energy

rarefaction


Crest◦ Top of wave

Trough◦ Bottom of wave

Amplitude◦ Distance from normal position to crest/trough

Waves & Energy


Displacement◦ Distance from crest to trough

Wavelength◦ Length of 1 wave◦ Distance between 2 crests/2 troughs

Frequency◦ Number of waves in a certain time

Waves & Energy


Vibrating particles◦ Carry the energy in a wave

Atoms◦ Gain energy◦ Absorb it◦ Re-emit it

Travel at m/s◦ Differ in wavelength & frequency

No sharp boundaries between types of waves◦ Overlap

Electromagnetic Waves


Gamma•Shortest wavelength•Can go through lead and concrete•Medical

X-Rays•Affect photographic film•Medical

Ultraviolet

•Beyond violet•‘Black light’•Cause skin cancer & sunburn•Sunbeds

Types of Electromagnetic Waves


Light

•Visible light

Infrared•Beside red light•Heat radiation•Passes through some gases and glass•Greenhouses•Trap•Heating



Microwaves

•Telecommunications•Make water molecules in food vibrate

Television & Radio Waves•Longest wavelength•TV & radio signals



Laser Light◦ Surgery

Intense heat Cut away unwanted tissues Burn off skin blemishes

◦ Shopping Read barcodes

Photonics◦ Using light in electric appliances

Waves & Technology


Satellites◦ cheaper than fixed lines◦ 35880km above the earth◦ Energy comes from solar cells◦ Remote areas

Receive all TV, radio and Internet services

Waves & Technology


Imaging◦ Being able to see where you cannot normally see

Medical Uses


Gamma radiation

•Patient given tiny dose of radioactive atoms•Recorded through gamma camera•Different types for diff parts of body

Ultrasound

•Very rapid vibrations•Not detected by our ears•Sound is reflected (echo) off diff parts inside body•Show unborn children, heart function, blood flow, treat kidney stones & gall stones

X-Rays•More absorbed by denser parts of body

Medical Uses


CAT Scans•CT scans•X-Rays concentrated on small slices•Computerised Axial Tomography•Detector records intensity of X-Rays

Treat Cancer

•Can kill cells•Particularly rapid growth ones

Medical Uses: X-Rays


Medical Uses: X-Ray ProtectionPlaced close to patient•Not scattered by dust

No-one else in room at

time

Machine placed in room with thick concrete walls•Absorb X-Rays

Entry to X-Ray room is along zig-zag hallway•Stops X-Rays being reflected into busy corridors

Radiation monitoring badges•Thermoluminescent dosimeters (TLDs)•Check radiation levels


Able to transmit energy◦ Without moving matter

Transverse waves◦ E.g. waves on the surface of water

Compression waves◦ E.g. sound waves

Vibrations◦ Cause sounds◦ Cause compressions & rarefactions

Waves


Medium◦ Material which waves travel through

Frequency◦ Number of complete waves made in 1 second

Pitch◦ Determined by frequency

Sound◦ Travels faster in solids & liquids than gases

Electromagnetic waves◦ Travel through air at ◦ Can travel through a vacuum

Waves


Not formed on lakes◦ Not enough space

Size of wave◦ Determined by strength + speed of wave

Diffraction◦ Waves spreading out when they approaches

shallower water Wave hits a cliff/breaks into a beach

◦ Kinetic energy sound + heat energy

Water Waves in the Ocean


Waver blows over ocean

Energy is transferred from

wind to wave



Breaking waves◦ Sucks up water to support itself

Not enough since gets shallower Rips

◦ Move straight out◦ Swim sideways if caught in one◦ No waves breaking◦ Used by surfers to get out quicker



Rays◦ Lines used to show the path of light

Beam◦ Stream of light rays◦ Visible

Particles in substances scatter it Transparent

◦ Most light travels through a substance Translucent

◦ Let just enough light to detect objects on other side◦ Can’t see objects clearly

Riding on a Light Beam


Opaque◦ Substances which absorb or reflect all light

striking them

Riding on a Light Beam


Reflections

Convex Mirror(Diverging mirror)

Concave mirror(Converging mirror)


Angle of incidence= angle of reflection

Reflections


Image◦ Something that we see that is not really where we

see it Image in curved mirror

◦ Distorted Concave mirror

◦ Enlarged image Convex mirror

◦ Wide view

Mirrors


Piece of glass/plastic with curved sides Shaped to bend light rays in new directions Shape of lens

◦ Amount of refraction of light◦ Size & type of image

Simple camera lens - convex◦ Focuses light to give sharp image on film

Convex lens at front of eye◦ Focuses light onto cells at the back of our eyes

Using Lenses


Changes in speed at the boundary◦ Bends towards normal

Refraction of Light


Rainbow◦ A spectrum of light

Light from sun = separated Dispersion

◦ Separation of light into its colours Filter

◦ Plastic sheet◦ Absorbs some colours but lets others pass

through

Colour


Tiny particles of dust & water vapour◦ Scatter light

Scatter blue better than red Reflected light from objects

◦ See objects

Colour


Red Orange Yellow

Green Blue Indigo

Violet

Colour


Colours of Light


Natural ResourcesTopic 6


Allows things to happen & change Cannot be seen Can never be used and destroyed Changes into other types of energy

◦ Most can’t be used again Energy efficiency

◦ Percentage of total energy that is used & not used Joules (J)

◦ Unit of measurement for energy 1000J=1 kilojoule

Energy


Fossil fuels◦ Non-renewable◦ Will be used up in the future

Non-renewable fuels◦ Cause many environmental problems

Renewable energy sources◦ Can be made again in the environment

Sustainable◦ Can be used in the future without problems:

Economic Environmental Social

Alternative Energy Sources


Don’t cause pollution Cheap

Readily available

Renewable

Alternative Energy Sources


Types of Alternative EnergyType Advantages Disadvantages

Hydroelectricity

• More rainwater is replenished in the dam

• Only sometimes suitable

• Disrupts the environment

Tidal energy • Works with environment • Expensive• Only some places are

suitable

Wave energy • Works with the environment

• Cost• Finding locations

Wind energy • Works with the environment

• Small power output per generator

Solar • Amount of suitable sites

Geothermal • Uses unutilised energy • Very limited locations

Biomass • Can make more valuable fuels


Fuels of the Future

•Fermentation of plant matterEthanol

•Electrolysis of waterHydrogen

•Methane & bacterial decay of animal matterBiomass


Greenhouse gases◦ Gases which trap some of the energy leaving the

Earth’s surface◦ E.g.

Carbon Dioxide Methane Chlorofluorocarbons (CFCs) Nitrogen oxides

Greenhouse effect◦ Heat from earth radiated towards surface◦ Supports life

Greenhouse Earth


Enhanced greenhouse effect◦ Burning of fossil fuels more greenhouse gases

Increase in amount of energy trapped in the atmosphere

Rise in temp of atmosphere◦ Clearing forests

For agriculture, paper production

Greenhouse Earth


Sources of Greenhouse GasesGreenhouse Gases

Main Sources

Carbon dioxide • Burning of coal• Burning of gas• Burning of oil

Methane • Livestock• E.g. cows

• Rice paddies• Mining

CFCs • Aerosols• Refrigerants in fridges and air-cons• Production of plastic foal• Dry cleaning

Nitrous oxides • Fertilisers• Burning of fossil fuels

• Especially petrol


⇒𝐶𝑎𝑟𝑏𝑜𝑛𝐷𝑖𝑜𝑥𝑖𝑑𝑒+𝑊𝑎𝑡𝑒𝑟Burning Fossil Fuels


Contained inside nucleus of atoms Fission

◦ Splitting an atom into 2 Protons and neutrons join together at random

Make 2 new atoms Not correct balance between neutrons, protons and

binding energy Eject excess ‘radioactive’

Nuclear Energy


Radioactive atoms◦ Unstable◦ Decay into stable atoms◦ Excess energy/subatomic particles are ejected

from nucleus Can damage surrounding cells

Fusion◦ Joining atoms of hydrogen to make helium◦ Produces huge amounts of energy◦ No radioactive waste products

Nuclear Energy


Chain reaction◦ Neutrons being thrown from an atom during

fission triggers more fission Nuclear medicine

◦ Radioactive chemicals to view tumours etc. inside the body

Nuclear radiation can cause tumours◦ Makes cells change

Including DNA

Nuclear Energy


Chain Reaction


Fission of a uranium-235 atom produces◦ A krypton atom◦ Barium atom◦ 3 neutrons◦ Gamma rays

Boron can absorb neutrons◦ Used in nuclear power stations

Control rods Change speed of reaction

Power from the nucleus


Nuclear power station◦ Heat from reaction

Changes water to steam◦ Steam drives turbines◦ Turbines drive generators◦ Generators produce electricity

Power from the Nucleus


Carbon-14 is radioactive◦ Nucleus is unstable due to extra neutrons

Compared to stable carbon-12

Radioactivity


•2 protons and 2 neutrons•Like helium nucleus•Shoot out at high speed but slow down in air•Paper and skin can stop them

Alpha Partic

les

Types of Radiation


•Fast electrons•Neutron breaks up forming a proton and an electron

•Pass through thin sheets of metal•Get through skin•20/30cm in air

Beta Partic

les

Types of Radiation


•High energy rays•Through thick sheets of metal•Except lead•Can pass deep into our bodies

Gamma rays

Types of Radiation


Geiger counter◦ Detects radiation

Half-life◦ Time taken for ½ of radioactive atoms in a sample

to decay Carbon dating

◦ Carbon atoms constantly being taken in when alive Including carbon-14

Decay slowly when die Age can be worked out

Radioactivity


47%

28%

8%

5%

4%

3%3% 2% 1%

OxygenSiliconAluminiumIronCalciumSodiumPotassiumMagnesiumOther elements

Elements in the Earth’s crust


Resource◦ Useful material/substance obtained from the

Earth Metals

◦ Obtained from minerals called ores Ore

◦ Economically important mineral◦ Useful quantities of a metal◦ Most are impure

Mixed with sand + other worthless materials Gangue

Earth Resources


Concentrate◦ Concentrated metal ore◦ Carried to smelter

Refined Through heating

Refining◦ Purification of metals◦ Electrolysis

Electrical energy used to deposit pure metal onto large electrodes

Earth Resources


Froth flotation◦ Method used to extract metals from impure

minerals◦ Make metals stick to kerosene bubbles

Earth Resources


Stone age◦ People used stone tools and implements

Ancient Egyptians◦ 1st people to smelt copper

Iron Age◦ Began: 1500-1000BC◦ Tech used to extract iron was developed◦ Iron tools were widely used

New Materials


Industrial Revolution◦ 1750-1800◦ Small workshops factories◦ Hand made machine made◦ Energy

No longer animals + moving water Now steam engines burning coal

Ceramics & plastics◦ Replacing metals in many uses◦ Creating new uses

New Materials


New materials from biological molecules Ages started at diff times in diff places

◦ Availability of resources was diff New plastics

◦ Kevlar◦ Polycarbonate◦ Terram

New Materials


• 1500-1000BC

Iron Age

• 3500BC-

Bronze Age

• 5000-2500BC

Copper Age

• 3000-5000 yrs ago

Stone age

New Materials

Andrew Newbound © Andrew Newbound 2013. Universe Huge space which contains all of the mater and...

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Transcript of Andrew Newbound © Andrew Newbound 2013. Universe Huge space which contains all of the mater and...