ackground Info.

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ackground Info. Chemistry - The study of matter & its changes Matter - Anything that has mass and takes up spa Examples of matter Examples of non-matter What kinds of changes can matter undergo?

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ackground Info. Chemistry -. The study of matter & its changes. Anything that has mass and takes up space. Matter -. Examples of matter Examples of non-matter. What kinds of changes can matter undergo?. Chemical Elements & Their Symbols. - PowerPoint PPT Presentation

Transcript of ackground Info.

Page 1: ackground Info.

ackground Info.

Chemistry - The study of matter & its changes

Matter -Anything that has mass and takes up space

Examples of matterExamples of non-matter

What kinds of changes can matter undergo?

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Chemical Elements & Their Symbols

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Where would you find a listing of all the elements?

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Element Symbols

Rules:made up of 1 or 2 letters

first letter is ALWAYS capitalized

If a second letter; ALWAYS lowercase

Ex: Sodium

na Na NA NA na

Which of the following represent elements?

C CO Co CU Cd

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Must learn some of the elements names / symbols:

(see handout)

Elements with symbols resembling their name:

Aluminum = AlCalcium = Ca

Zinc = ZnNitrogen = N

These are easier to memorize

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Elements with symbols derived from foreign names: MUCH harder to memorize!

Element Name Older Foreign Name SymbolDo not need to know this!

Antimony Stibium Sb

Tungsten Wolfram W

Lead Plumbum Pb

Copper Cuprum Cu

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ALL elements & their symbolsthat are on the handout

These are not all the known elements,but they are the ones we will encounter in our everyday lives

You will have a QUIZ on them ________________!!!

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Element -Substance where all atoms are the same

~ 110 elements known todaylisted on periodic table

some are common, some are rare

can be solids, liquids or gases at room temperaturesome are synthetic

ALL matter is made up of elements

BONUS POINTS: Bring in a sample of an element tomorrow

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Compound -Substance made up of 2 or more elements (always in the same proportions)

Can you name some compounds?

Water H2O

Carbon dioxide CO2

Table salt NaCl

Carbon monoxideCO

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Nearly all advances in science have BOTH good & bad aspects

Examples: pesticides

DNA libraries

stem cell research

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(Francis Bacon)

Points out the “Goods” of science

(Rachel Carson)

Points out the “Bads” of science

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How do we know if we should usea particular scientific invention?

Weigh the risks and the benefits

any hazard,loss, injury

positive effects,promotes well-being

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(DQ)

DQ = Benefits Risks

If benefits & risk DQ is

If benefits & risk DQ is

HIGH

LOW

would use

would NOT use

If benefits & risks are = DQ difficult to determine

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Let’s do a couple together:

Depends on the point of view for individualfor whole society

Pasteurized milkThalidomide (morning sickness drug 1950’s)Aspartame (artificial sweetener)Nuclear powerOlean (low-fat potato chips)Cloning

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Project

Pick ONE scientific / medical / technical invention

Make a list of the “goods” & “bads” of this invention

Prepare a display of this invention along with its benefits & risks

(see examples from previous classes)

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Reading Labels:

FIRST ingredient listed -Present in the highest amount

If sugar is first, product has more sugar than anything else

Active vs. Inert Ingredients

Make the productperform

UnreactiveDOES NOT help

performance

Web Quiz

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Antioxidants -Used in consumer products

to keep fats / oils frombecoming rancid

Smell & taste bad

against oxygen

Fat / oil + O2 spoiled foul smelling &

bad tasting chemicals

Antioxidants react with O2 before it can react with the fat or oil

Keeps product fresh longer!

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2 Types of Antioxidants:

Natural - Vitamin CVitamin EVitamin A

Synthetic -Made in a laboratory

BHA (butylated hydroxyanisole)

BHT (butylated hydroxytoluene)

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1. Find a product that contains BHA or BHT

2. Give product name

3. List first 5 ingredients

4. Does it contain BHA or BHT?

Due: __________________

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Mass vs. Weight

Mass -A measure of the amount of mattersomething contains

Weight -A measure of the force of gravity on an object

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Mass is the SAME EVERYWHERE

Weight DEPENDS ON LOCATION

prefer mass for this reason

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The Metric System

Used all over the world except in the U.S.

ALL scientists measure in the metric system

Easier than English system because it is based on:

1

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Length =

Mass =

Volume =

meter

gram

liter

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Metric Prefixes

BaseUnit

meter,gram,liter

Prefix

Abbreviation

Relation to base unit

kilo

k

1000

deci

d

1/10

centi

c

1/100

milli

m

1/1000

Larger thanbase unit

Smaller thanbase unit

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Estimating Metric Measurements

Length1 m 1 yard

1 cm width of pinky1 mm width of dime

Mass1 g paper clip

1 kg 2 lbs.

Volume1 L 1 quart4 L 1 gallon

1 mL 10 drops

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Let’s try some! (anyone want a calculator?)

15 gal gas tank ~ 60 L

Dr. Lotter 140 lb. ~ 70 kg

Textbook ? kg ~ 1 kg

Pen ? g ~ 10 g

Your height ~1-2 m

Length of textbook ? cm ~ 25 cm

Width of a nickel ? mm ~ 3 mm

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oF oC

Boiling pt. of water

Freezing pt. of water

212 o

32 o

100 o

0 o

Which is ALWAYS smaller? Celsius!(keep this in mind)

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Converting Temperatures

1. Add 40

2. Multiply or Divide by 1.8

3. Subtract 40

(must do all steps or it won’t work)

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This classroom is about 70 oF.What is the temperature in oC?

70+ 40 110

Should we x or ?Celsius is always smaller

Should !

110 1.8 = 61

61- 40 21 Answer = 21 oC

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Now you try alone:

100 oC = ________oF

100+ 40 140

Must x since oF is always larger

140 x 1.8 = 252

252- 40212 Answer = 212 oF

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States of MatterSolid

Liquid

Gas

(Plasma)

Let’s learn more about these states through experiment

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Solid Liquid Gas

Shape

Volume

Position ofMolecules

Compressibility

Definite

Definite Definite

IndefiniteIndefinite

Indefinite

Close Close Far Apart

NO NO Yes

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Solid Liquid Gasmelting evaporation

condensationfreezing

sublimation

ADD Heat

REMOVE Heat

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Physical Property -Can be observed with your sensesNo reaction with another substance

Chemical Property -Must have a reaction in order to seecolor, odor, hardness, melting point

flammable, oxidizes

Physical Change -happens with NO change in thechemistry of the substance

Chemical Change -Substance changes into a new substance

could reverse change

CANNOT reverse change withoutdoing a chemical reaction

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Pure Substances -Always have the same composition

1. Element – made up of only 1 type of atom

Al, C, H, O2, U, Fe, Au

H2O, CO, CO2, NaCl

2. Compound – 2 or more types of atoms in a definite proportion

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Mixtures -have a variable proportioncan be physically separated

salt + water

iron + sand

oil + water

sugar + sand

sand + water

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2 Types of Mixtures:

1. Homogeneous -The same throughout

2. Heterogeneous -Different in spots

Kool-Aid, chocolate ice cream

sand + water, chocolate chip ice cream

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Matter

SubstancesFixed composition

MixturesVariable composition

ElementOne type of atom

Compound2 types of atoms

HomogeneousSame throughout

HeterogeneousDifferent in spots