1. What is Matter?
Chapter 2.1

2. Goals Explain the relationship between matter, atoms, and elements
Distinguish between elements and compounds
Describe molecules and how they are formed
Interpret and write some common chemical formulas
Categorize materials as pure substances or mixtures

3. What is Chemistry?? Chemistry is…“the study of matter and its changes”
So what is matter?? Anything that has mass and takes up space!

4. Matter quiz! Is a doorknob matter? Is a shadow matter?
Yes!
Is a shadow matter?
No.
Is a laugh matter?
Is a pencil matter?
Is an atom matter?

5. What is an element??
A substance that cannot be separated or broken down into simpler substance by chemical means (Check out the Periodic Table of Elements!)
You cannot break down carbon, oxygen, etc. into any other element or compound
Name some other elements…

6. What is an atom?
The smallest unit of an element that maintains the properties of that element
Ex: An atom of carbon
Atoms have distinct properties specific to the element they represent
Atoms are composed of protons, neutrons, and electrons

7. Building up to…Compounds
A substance made of atoms of 2 or more different elements that are chemically combined
Ex: Nylon
What kinds of atoms do you think nylon is made of?
Carbon, hydrogen, nitrogen, and oxygen

8. On a separate piece of paper…create 2 pie charts…
Label and fill in the percentages of what you think the human body is composed of…
Include nitrogen, sulfur, carbon, oxygen, potassium, calcium, phosphorus
Label and fill in the percentages of what you think the Earth as a whole is composed of…
Include oxygen, nickel, magnesium, sulfur, silicon, iron, and calcium

10. So what’s a molecule?
Atoms combine and act as a unit, known as a molecule
The smallest unit of a substance that keeps all of the physical and chemical properties of that substance.
So if you pull apart one molecule of a substance, it will have the same properties of a bunch of molecules combined
Example: H2O (the atoms combine and act as one water molecule unit)

11. Molecules
Molecules may be combinations of atoms of the same element or different elements
So…H2O is a molecule, but so is O2
How do you represent a molecule of table salt?
NaCl (Sodium chloride)

12. Chemical Formulas
A combination of chemical symbols and numbers to represent a substance
What is the chemical formula for water?
What is the chemical formula for salt?
What is the chemical formula for sugar (glucose)?
How many atoms are present in each of the substances above?

13. Pure Substances vs. Mixtures
Pure substances  a sample of matter (either a single element or a single compound) that has definite chemical and physical properties
Example: Water
Mixture  a combination of two or more substances that are not chemically combined
Example: Oil and Water
Example: Cereal and Milk

14. Classifying Mixtures
Heterogeneous—mixtures that are not evenly distributed (“hetero” = different)
Example: Flour in Water, Sandy Water, Chicken Noodle Soup
Homogeneous –mixtures that are evenly distributed (“homo” = same)
You cannot see the separate parts of a homogeneous mixture
Examples: Blood, Sugar Water, Salt Water, Gasoline

15. …Classifying Liquid Mixtures…
Miscible  a mixture that “totally mixes”
the parts dissolve into each other and the mixture does not separate
Miscible liquids form homogeneous solutions
Example: Ethanol and Water, Salt and Water
Immiscible  a mixture where the parts do not dissolve into one another
The parts will separate with time
Example: Oil and Water

16. Gases can also mix with liquids…
Examples?
Carbonated beverages
Are these homogenous or heterogeneous mixtures?
Lemon meringue pie
Lava
Pumice rocks