Matter Unit 1. Warm Up 1/26/2015 Complete the following unit conversions: How many grams are in 10...
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Transcript of Matter Unit 1. Warm Up 1/26/2015 Complete the following unit conversions: How many grams are in 10...
MatterUnit 1
Warm Up 1/26/2015
Complete the following unit conversions:How many grams are in 10 kilograms?How many meters are in 45
centimeters?How many deciliters are in 0.5 liters?
Reminders
Elements Quiz WednesdayFirst Test Friday
ACT Vocabulary
Arid – extremely dryHaughty – arrogant;
condescendingDeleterious - harmfulJubilation – joy; exultationAbbreviate – to shorten, abridge
Defining Matter
Matter
What it is: What it is not:
Examples: How to measure:
Matter = “Stuff”
Matter is anything that has mass and occupies space. a. Mass - measured in grams b. Space (volume): measured in mL or cm3
Matter - Not Matter – Not Sure
Sort the following words into 3 categories:
Peanut butter Yourself Plastic food wrap Cotton fabric Time Carbon dioxide Light Water Air Energy Motion Fish An idea Garbage
Properties and Changes in Matter A. Physical Properties 1. A characteristic that can be observed or
measured without changing the identity of the substance.
What are some examples?
B. Chemical Properties and Change
1. The ability of a substance to undergo changes that transforms it into different substance
This means: It will have a new chemical formula. When it changes, it will undergo a chemical change.
We look for these Indicators of chemical change:
1. color changes2. gas produced3. temperature change4. new substance formed 5. odor released
Classifying Matter into Major Categories
Pure Substances Pure Substance is matter for
which a chemical symbol or formula can be written.
Mixtures Mixtures of matter are not
chemically bonded and can be in any proportion.
Classify these examples matterSodium Water Soil Coffee Oxygen Soup Salt WaterIron Ice Cream Nitrogen Eggs BloodTable Salt Milk Cola Air
Pure SubstancesElement
Composed of identical atomsEx. Copper wire, aluminum foil
Pure Substances
• Element– composed of identical atoms
– EX: copper wire, aluminum foil
Pure Substances
CompoundComposed of 2 or more elements in a fixed ratio
Properties differ from those of individual elements
Ex. Table salt (NaCl)
Mixtures
Variable combination of 2 or more pure substances
Mixtures
Substances are mixed together but they do not react to form new substances.No chemical reactionCan be separated physically– such as
filtering, dismantling, etc.They can be mixed in different proportions
Heterogeneous: can see the parts Homogeneous: looks uniform
Also called solutions Can easily be mistaken to be a
compound
Mixtures
Matter
Pure Substance
element
Example
Example
compound
Example
Example
Mixtures
Homogeneous
Example
Example
Heterogeneous
Example
Example
Homework!
Find 5 examples of each type of matter (HINT: there are 4 types!)
Unit Conversions
How many Liters are in 670 mL ?
How many cg are in 1.25 grams?
How many mL are in 0.215 kL?
Energy Introduction
F. Energy is always involved in physical and chemical change
Energy definition: ability to transfer heat or do work
Examples of energy sources1. Chemical2. Nuclear 3. Kinetic4. Electrical5. Gravity (or
positional)
Heat and temperature are different
• Key concept in chemistry
• Heat is a form of energy (measured in joules)
• Temperature is a measure of hotness or coldness (measured in ºC or K)
• Actually the average kinetic energy of the atoms
When a scientist heats a substance, she is adding ___________.
This results in the atoms in the substance moving ___________ and so the temperature increases.
What about Temperature?
We all know that some things feel hot, and others cold, but is there more to temperature than that?
When an object feels hot, the atoms inside it are moving fast in random directions, and when it feels cold, they are moving slowly. Our body interprets that random atomic motion into what we feel as hot and cold, and a thermometer interprets that atomic motion as a certain number of degrees.
So when I'm heating something, I'm just making its atoms move faster?
Exactly. If the object is a solid the atoms are vibrating back and forth, and if it is a gas like the air, the atoms are flying around much like little balls.
Energy, usually in the form of heat, is involved in changes of state (phase changes.)
Heat is __________________. Therefore, it is a _______________ change.
Heat is __________________. Therefore, it is a _______________ change.
Phase change
Phase change
Solid
Endothermic – energy absorbed
Exothermic – energy released
Change of State (phase changes)
Phase change The change is called:
Is it exothermic or endothermic?
Everyday example
Solid to liquid
Liquid to gas
Solid to gas
Gas to liquid
Liquid to solid
Gas to solid
F. Energy is always involved in physical and chemical change1. Exothermic:
We use the words:
2. Endothermic
We use the words:
The Law of Conservation of Energy
• Energy is neither _______________ nor
______________ in a chemical reaction.
Density
Physical property can be measured without destroying the
sample
Use: to identify substances & product design
Density = mass
volume
• Density = mass (g) SOLID
volume (cm³)
• Density = mass (g) LIQUID
volume (mL)
Measurements needed to determine density
Density: Example Problems 1. What is the density of a solid with a mass of 200 grams
and a volume of 40 cm³?
2. What is the density of a liquid which is measured at 25 grams and 20 mL?
3. What is the density of a piece of metal which is
2 cm x 5 cm x 3 cm and weighs 350 grams?
Density Formula
To change to formula
(2) Cross multiple or
(2) Slide the variables diagonally across the equal sign
D = M V
Density Calculation Practice D = M V
Problem 1: A block of metal has a mass of 250 grams. The volume of 31.8 cm³. What is its density? Identify the metal.
Problem 2: Aluminum has a density of 2.70 g/ cm³.
The Al rod has a volume of 50 cm³. What is its mass?
Problem 3: Gold has a density of 19.31g/ cm³. A gold coin has a mass of 200 grams. What is the volume of the coin?
Rem
em
ber:
n
o n
aked
n
um
bers
!
Why do substances have different density?- Identify and then write an explanation
Why do substances have different densities?
Explanation: Structure:
Atoms of the substance:
Energy
Feedback: Rate your understanding of the following topics: Rating system: 1= confused 2= Fair but topic is not clear in my mind 3= Understand the topics but need more
practice 4= Good, some practice & review will help. 5= Excellent, I know the topic and can do the
problems.
For ratings 1 & 2: tell us what will help you
Feedback: Label
Units in chemistry & prefixes
Factor Label method - Unit conversions
Properties of Matter
Energy involved in changes
Classifying matter – pure substances & mixtures
Density calculations
LINKS
Matter song
https://www.youtube.com/watch?v=Sri3ItB8JvA
Matter properties (Issac)
https://www.youtube.com/watch?v=WGhGcrTVDVI
Matter properties parody
https://www.youtube.com/watch?v=EeWzyR1xap4