Period 4
Period 5
Period 6
Describing Matter (2.1)
The Nature of Matter
Changes in Matter (2.2)
Energy and Matter(2.3)
Just the
Facts
Chapter 2 – Self Check
1. Get out Chapter 2 info sheet
3. Read and mark your facts
and definitions.
Need more practice
Have a question
Feel confident
Ch 2 Practice Points
Workbook
Answer the questions that you find interesting or challenging. Answer at least one
question from each section. Read all the questions. 1 point for each correct answer.
Chemical vs. Physical Properties:
Make a Venn diagram to compare and contrast physical and chemical properties.
Include at least 5 unique points for each and 3 similarities.
Law of Conservation of Matter Classroom Display:
Research Antoine Lavoisier. Create a classroom display using pictures and writing to
describe the experiments he performed that were the basis for the law of
conservation of matter.
Energy Extend Assignment:
Make a slide show presentation that explains each of the 4 types of energy
describe in your textbook. Be sure to include text and pictures on each slide. Use
appropriate vocabulary.
Vocabulary Flash Cards:
Make flash cards with word, definition, and picture for each of the 10 essential
words for this chapter.
Chapter 2 Vocabulary
Matter
Physical Property
Chemical Property
Element
Atom
Chemical Bond
Molecule
Compound
Chemical Formula
1.
2.
3.
4.
Law of Conservation of Matter
Solution
VOCAB CLASSWORK
Physical Change
Fold your paper into 16 boxes
Chemical Change
Pick 16 words
In each box include:
Energy
• Correctly spelled word
Thermal Energy
• Glossary definition
Endothermic Change
• Picture to help you
remember definition
Exothermic Change
• An example
Chemical Energy
This note page should be used
for studying to prepare for
Friday’s quiz and next Friday’s
chapter 2 Test.
1: Properties of Matter
2: Elements
3: Compounds
4: Mixtures
Describing Matter
Section 2.1
Page 58
Forms of
Matter
What are
some
examples?
Matter
(takes up space
and has mass)
All
Mixed
Up
Mixture
Pure Substance
(2+ substances, not chemically
bonded, no set ratio)
(single kind of matter with
distinct properties)
Molecule
Heterogeneous
Homogeneous
Element
(2+ atoms)
(parts visible)
(parts indistinguishable)
(types of atoms)
Compound
(2+ elements)
Fact 1: Properties of Matter
Physical Properties
• Can be observed
without changing it into
another substance
• Examples:
– Read page 60
•Density
•Magnetism
– Discuss
•Melting
pointat table
•Conductivity
•Texture
– List on note •Luster
page
•Color
•Hardness
•Flexibility
Prop.
Quiz
Show
Chemical Properties
• Describes ability to
change into different
substances
• Must observe through
experimentation, not
just by looking or
touching
• Flammable
• Examples:
• Can Tarnish
• Can Rust
Test Tube Detective
Fact 5: Ch-Ch-Ch-Changes
Physical Changes
Chemical Changes
• Alters form or appearance
• Does not change the
substance
• Examples – Change in State
• Transforms the substance into
a different substance
• Substance breaks down
• Substances combine
• Examples
A substance that
undergoes
a
– To Liquid
– To Solid change is
physical
– To Gas
• Examples
– Change
in Form
still the
same
– Dissolving
– Bending
substance
after
– Crushing
change.
–the
Breaking
– Chopping
A chemical change
produces new
– Chemical reaction with
substances
– Combustion (burning)
– Oxidation (metal
reacts with
properties
different
oxygen)
– Tarnishing
(metal reacts
with
from
those
of
the
sulfur)
– Electrolysis
(electricity breaks
original
substances.
down a substance)
Fact 6: Energy
• All physical or chemical changes involve
absorption or release of energy
– Endothermic = absorbs energy
Endothermic vs. Exothermic
– Exothermic = releases energy
• Types of Energy:
– Thermal (movement of molecules, heat)
– Chemical (stored in chemical bonds)
– Electromagnetic (wave energy, light)
– Electrical (movement of charged particles)
A Couple of Laws
• Law of Conservation of Matter/Mass: Matter
is not created or destroyed during chemical or
physical changes; it just changes form
• Law of Conservation of Energy: Energy cannot
be created or destroyed; it can just change
form.
Sorting Activity
1. Look at the cards in your bag.
2. With your table, sort them into physical changes or
chemical changes.
3. Make sure everyone in your group agrees
4. Participate with the class to check your answers
5. Record the examples on your note page
Physical Change Examples
Chemical Change Examples
Check your Answers
Hold up PINK for PHYSICAL CHANGE
Hold up BLUE for CHEMICAL CHANGE
Elements, Compounds, and Mixtures
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Compound (B)
Mixture of Elements (C)
Mixture of Compounds and Elements (E)
Mixture of Compounds (D)
Element (A)
Compound (B)
Element (A)
Mixture of Compounds and Elements (E)
Mixture of Elements (C)
Mixture of Compounds and Elements (E)
Compound (B)
Compound (B)
Mixture of Compounds (D)
Mixture of Compounds (D)
Mixture of Compounds (D)
Substance vs. Mixtures
1.
2.
3.
4.
5.
Sodium – Na – Element
Water – H2O – Compound
Soil – Mixture
Oxygen – O – Element
Alcohol - CH3CH2OH –
Compound
6. Carbon Dioxide – CO2 –
Compound
7. Cake Batter – Mixture
8. Air - Mixture
9. Soup – Mixture
10. Salt Water – Mixture
11. Ice Cream – Mixture
12. Nitrogen – N – Element
13. Eggs – Mixture
14. Blood – Mixture
15. Table Salt – NaCl –
Compound
16. Cola - Mixture
Heterogeneous vs. Homogeneous
1. Flat Soda Pop –
Homogeneous
2. Cherry Vanilla Ice Cream
– Heterogeneous
3. Salad Dressing –
Heterogeneous (usually)
4. Sugar Water –
Homogeneous
5. Skip
6. Spaghetti Sauce –
Heterogeneous (usually)
7. Soil – Heterogeneous
8. Paint – Homogeneous
9. Pure Air – Homogeneous
10. City Air – Heterogeneous
11. Coffee – Homogeneous
12. Steel - Homogeneous
Toasty Marshmallow Lab
• Purpose: Observed chemical changes caused
by changes in energy.
• Background: Define endothermic and
exothermic change.
• Data:
Temperature of
Water Before
Temperature of
Water After
Toasty Marshmallows – p73
1. Add 20mL water to an empty soda can and
record temperature.
2. Place the mini marshmallow on the paperclip
contraption.
3. Hold the can of water over the marshmallow.
USE TONGS.
4. Light the marshmallow and wait for it to
completely burn.
5. Record the temperature of the water.
Toasty Marshmallows Analysis
• Conclusion: Use paragraph format and
address all questions.
– Did the temperature of the water change? Why?
– What evidence of a chemical change did you
observe?
– What kind of energy was released?
– Where was the energy originally stored?
– Was the reaction exothermic or endothermic?
Matter
Anything that has mass and takes up space
 All the “stuff” around you is matter
 Matter can be divided into two categories:
mixtures and pure substances

Pure Substances
Substances that are a single kind of matter
 Always has the same make up and
properties no matter where it comes from
 Ex: table salt- always comes from seawater
or a salt mine

Elements
A pure substance that CANNOT be
broken down into any other substance
 They are the simplest substance
 Ex: carbon, calcium

Compound
Made up of two or more elements
chemically combined
 Ex: Water- hydrogen and oxygen

Mixtures
Made up of two or more substances
(elements or compounds) but they DO
NOT chemically combine
 They CAN be separated

Granite Rock
Heterogeneous Mixture
You can see the different parts
 Separate the parts easily
 Ex: Salad or sand and flour

Homogenous Mix - Solutions
A very well mixed mixture
 Can’t see or tell that there are different
parts even though there are
 Ex: sugar water – can’t tell the sugar from
the water after mixing

Practice Questions


Try to answer without looking at your notes or
reviewing the previous slides
Once you decide on an answer, go back and see
if you were right.
Question 1:
a.
b.
c.
d.
What would salt water be considered?
An element
A compound
A solution or homogenous mixture
A heterogeneous mixture
Question 2:
Which is an example of a heterogeneous
mixture?
a. Fruit punch
b. Sand and rocks
c. Sugar water
d. Kool-Aid
Question 3:
Matter can be divided into two categories,
what are they?
Mixtures and Pure Substances
All Mixed Up
Homogenous vs. Heterogeneous Mixtures
• Purpose: How can you tell a homogeneous
mixture from a heterogeneous mixture? (What
will you do?)
• Background: What is a heterogeneous mixture?
What is a homogeneous mixture? (Describe each
type of mixture)
Discuss answers at your table, then record
onto your lab report.
All Mixed Up
• Procedure: Carefully look at each test tube and
record your observations. You may smell (waft)
but don’t taste.
• Data: (Copy this data table onto your lab report)
Test Tube
1
2
3
4
5
6
Substance
Well Mixed or
Separated?
Heterogeneous or
Homogeneous Mixture?
All Mixed Up
• Conclusion: What is the main difference
between homogeneous and heterogeneous
mixtures? What sense do you use to
determine whether a mixture if homogeneous
or heterogeneous?
All Mixed Up: Test Tubes
1
2
3
4
5
6
Test Tube Detective
• Purpose: Observe physical and chemical
properties to identify an unknown sample.
• Background: What is a chemical property?
What is a physical property? List examples of
each.
Discuss answers at your table, then record
onto your lab report.
Test Tube Detective
• Procedure:
1. Observe and record physical properties: what does it
look like (use magnifier), what does it feel like, what
does it smell like (waft!)
2. Start with baking soda, put 0.5mL into each test
tube. Then add a dropper full of vinegar, water,
iodine into the corresponding test tube. Record
observations
3. Clean out test tubes and repeat with each of the
remaining known samples.
4. Perform the same test on the unknown sample.
5. Identify the unknown by comparing to your
observations of the known samples.
Test Tube Detectives – Data Table
Substance
Baking
Soda
Baking
Powder
Cornstarch
Baby
Powder
Unknown
Physical Properties
Chemical
Property
with
Vinegar
Chemical
Property
with
Water
Chemical
Property
with
Iodine
Test Tube Detectives
• Conclusion
– What physical properties did you observe?
– What chemical properties did you observe?
– What is the identity of your unknown substance?
– What properties helped you determine the
unknown?
Chemical vs. Physical
Changes
Physical Changes, P. 68-72



Physical changes involve
altering the form of a
substance, but does not
change it to another
substance.
Ex: bending a nail, tearing
paper, making playdough
changing states of matter –
boiling water, freezing
popsicle, mixing koolaid, etc…
Changes of State


All changes of state are physical changes.
All state changes involve loss or gain of thermal
energy
Chemical Changes Defined




During a chemical change,
matter is changed into a new
substance with new properties.
Ex: burning wood – wood to
ash and gases
Other examples: baking a
cake, glow sticks, making toast,
mixing vinegar and baking
soda, milk ‘curdling’, etc…
Think of a chemical change of
when you can’t change the new
substance back to it’s original
form.
Chemical Changes





Chemical changes = chemical reactions
In all chemical reactions, new substances are
produced.
All reactions either release or absorb energy.
Ex: of absorption – plant growth, cold packs.
Ex: of release – digestion, baking, lighting a
match, burning wood
Law of Conservation of Matter


Matter is not created or destroyed in any chemical or
physical change.
Mass of reactants always equals the mass of the
products
Energy and Change




During physical and chemical changes,
energy is either added or taken away.
Thermal energy is energy from molecule
movement (heat)
Chemical energy is the energy from the
bonds between molecules in a substance.
Law of conservation of energy – during any
chem. Or phys. Change, amount of energy
stays the same.
Examples of conservation of
Energy



Unlit match contains
chemical energy
When lit – energy
converted to thermal and
light energy.
Amount of energy
remains the same, just
changes form.