1. Unit 1: The Atom/Matter
Aim: How to identify types of matter? Do Now: In your notebook write down what you think everything is made up of

2. What is chemistry? Chemistry is the study of matter What is matter?
Matter is anything that has mass and takes up space
Is air matter? Discuss in pairs

3. What is an atom? An atom is the most basic particle of all matter
Everything is made up of different atoms.
We often draw atoms as circles.

5. What is a substance Elements and compounds are considered substances
A substance is matter that has a uniform and definite(or fixed) composition.
O2 oxygen molecule

6. What is an element?
An element is made up of one TYPE of atom, like carbon, gold or chlorine
The atoms of a specific element are the same as each other, and they are different from the atoms of all other elements.
A molecule of an element is formed when two or more atoms of the same element chemically join together (ex: O2 is made up 2 atoms of the element oxygen).
Molecules of the element oxygen
(multiple atoms of the same element)
Helium atoms
(single atoms of an element)

7. What is a compound?
A compound is a substance that contains atoms of two or more different elements chemically joined together in a fixed ratio.
Carbon dioxide
(CO2)
Ratio
1 Carbon atom:2 Oxygen atoms
Water (H2O)
Ratio 2Hydrogen atoms : 1 Oxygen atom

8. Properties of compounds
A compounds has different properties from the individual elements that make it up.
Example: H2O is a liquid at room temperature, where has H2 hydrogen and O2 oxygen are gases at room temperature

9. Compounds vs Elements
Compounds can be broken down chemically into smaller substances, elements cannot.

10. What are mixtures?
A mixture is a physical blend of two or more components.
Components do not have fixed ratio
Heterogeneous mixtures are a mixture in which the composition is not uniform throughout. (can see the different part)
Oil and vinegar, chicken noodle soup
Homogeneous mixtures or solutions are mixtures in which the composition is uniform throughout.
(Cannot see different parts)
oil, vinegar, cup of coffee, salt water

11. How to separate mixtures?
All components of a mixture keep their individual properties
Since a mixture is a physical blend of the components, then physical means can be used to separate mixtures.

12. Mixture
Compound
Composition
Variable composition – you can vary the amount of each substance in a mixture.
Definite composition – you cannot vary the amount of each element in a compound.
Joined or not
The different substances are not chemically joined together.
The different elements are chemically joined together.
Properties
Each substance in the mixture keeps its own properties.
The compound has properties different from the elements it contains.
Separation
Each substance is easily separated from the mixture.
It can only be separated into its elements using chemical reactions.
Examples
Air, sea water, most rocks.
Water, carbon dioxide, magnesium oxide, sodium chloride.

13. Description
Example
Diagram
Pure element
Oxygen (O2)
Pure compound
Carbon dioxide (CO2)
Mixture of elements
Oxygen (O2) and Helium (He)
Mixture of Compounds
Alcohol (C2H5OH) and Water (H2O)
Mixture of elements and compounds
Air (O2, N2, CO2, H2O)

14. yes
yes

15. Sample Problems
Which substance can not be decomposed into simpler substances?
(1) ammonia (NH3)
(2) aluminum (Al)
(3)methane (CH4)
(4)methanol (CH3OH)
Answer: choice 2 aluminum is an element. It is a pure substance and cannot be broken down by any means into simpler parts. The other choices are compounds

16. Sample Problems cont.
Which statement describes a characteristic of all compounds?
(1) Compounds contain one element, only.
(2) Compounds contain two elements, only.
(3) Compounds can be decomposed by chemical means.
(4) Compounds can be decomposed by physical means.
Answer: Choice 3 A compound can be decomposed by a chemical change. It is made of two or more different elements chemically united in a definite ratio.

17. Sample Problems cont.
Which formula represents a binary (two different types of elements) compound?
(1) NH4NO3
(2) CH4
(3) CH3COCH3
(4) CaCO3
Answer: Choice 2 CH4 is composed of two elements: carbon and hydrogen

18. Sample Problems cont.
An example of a heterogeneous (can tell apart the different parts in the mixture) mixture is:
(1) soil
(2) sugar
(3) carbon monoxide
(4) carbon dioxide
Answer: Choice 1 Soil has minerals, rocks, dirt, bacteria, etc., all mixed together; different parts of the soil have different amounts of materials.