Chemistry
Chapter 2
Section 1 Properties of Matter
Big Idea
"Chemistry As The Central Science"
Describing Matter
*All matter has mass and takes up space *Mass = measure of the amount of matter the object contains
*Volume = the amount of space an object takes up
*Extensive Property = depends on the amount of matter in a sample
Describing Matter
*Intensive Property = depends on the type of matter in a sample, not the amount of matter
*Take types of soda for example: *Which one has the most sugar?
*Sugar is an example of an intensive property
Describing Matter
*Substance = matter that has a uniform and definite composition
*All samples of the same substance have IDENTICAL intensive properties
*Physical Properties = A quality or condition of a substance that can be observed or
measured without changing the substance's composition
What are some physical properties of this bowling ball? States of Matter
Solid
Liquid
Gas
Vapor
Definite
Shape? Definite Volume?
Other Info:
Yes
Yes
Yes
No
No
No
No
No
Compre-ssible?
No
No
Yes
Yes
Gas at room temp Liquid at room temp
Expand When Heated?
Very Little Very Little Yes
Physical Changes
*Physical Change = Some properties of the material change but the composition does not!
*Can be reversible and irreversible
Classwork
*Mini Lab on next slides
*2.1 Lesson Check # 1 - 9
Homework
*Read 2.2 & 2.3
*SG 2.1
Mini Lab: Solid, Liquid, or What?
You need a measuring spoon, cornstarch, a small bowl, and water
1. Add 1/3 cup of cornstarch to the bowl and then 1/3 cup of water
2. Stir the contents and let stand for 5 minutes 3. Slowly push your finger into the mixture. Repeat with your fist.
4. Quickly jab your finger into the mixture. Repeat with your fist.
5. Take a handful of the mixture and form a ball. Squeeze and release the ball several times.
6. Answer the questions on the next slide to help you with your QCE sheet
1. What happens when you slowly push into the mixture with your finger or fist?
2. When you jab it quickly? 3. When you squeeze the ball? 4. When you release the ball?
5. What condition seems to determine whether the mixture behaves like a solid or a liquid?
With your group fill out a QCE sheet. Post on the back wall....collaborate...turn in finished product.
Chemistry
Chapter 2
Section 2 Mixtures
Big Idea
"Chemistry as the Central Science"
Classifying Mixtures
Classifying Mixtures
Heterogeneous Homogeneous
*Not uniform throughout *Uniform throughout *AKA a solution
*Many are liquid, but some are solids or gases *Only 1 phase *More than 1 phase
Separating Mixtures
*Many ways to do this!
*Filtration *Distillation
*Look at the properties and find what differs *Use that to separate
*How could I separate iron filings from table salt?
Class Activity!
* I will separate you into different groups.
Classwork
*2.2 Lesson Check #12 - 19
Homework *SG 2.2
Chemistry
Chapter 2
Section 3
Elements & Compounds
Big Idea
"Chemistry as the Central Science"
Distinguishing Elements & Compounds
* Element = simplest form of matter that has a unique set of properties
*Listed on the Periodic Table
*Cannot be broken down chemically into simpler substances
*Always a substance, never a mixture
*Compound = substance that contains two or more elements
*Can be broken down chemically into simpler substances
Element
Compound
Gold
Water Zinc
Titanium
Air
Distinguishing Elements & Compounds
*A Chemical Change = produces matter with a different composition than the original matter
*Properties of Compounds
*Usually very different than the elements that make them up
Distinguishing Substances & Mixtures
Can be separated physically to form
Can be separated chemically to form
Symbols & Formulas
*Each element is represented by a one or two letter chemical symbol
*Pb = Lead *O = Oxygen *Mg = Magnesium *N = Nitrogen
*When only one letter - uppercase
*When two letters - first uppercase & second lowercase
The Periodic Table - A Preview
*Separated into groups based on on a set of repeating properties
Period, properties vary
G r o u p
Similar chemical & physical properties
Classwork
*2.3 Lesson Check # 22 - 31
Homework
Chemistry
Chapter 2
Section 4 Chemical Reactions
Big Idea
"Chemistry as the Central Science"
Chemical Changes
*Chemical Property = The ability of a substance to undergo a specific chemical change
*Iron can rust = chemical property
*Remember that during a chemical change the composition ALWAYS changes
*Also called chemical reactions Sugar Carbon + WaterHeat Reactant(s) Product(s)
Recognizing Chemical Changes
*Four clues
1. Involves transfer of energy 2. Change in color
3. Production of a gas
4. Production of a solid (aka precipitate)
*Just because one of these happen doesn't mean for sure that a chemical change happened
*The only way to be sure that a chemical change happened is to test the composition before and after
Conservation of Mass
*States that mass is never created nor destroyed
*This means that during any change (physical or chemical) the total mass of the reactant(s) is exactly equal to the total mass of the product(s)!
Fe + S FeS
What if... 10g?
35g
?
10g 10g