Chemistry and Matter
What is chemistry?
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Chemistry is the study of matter, its properties, and its changes or transformations.
Why is it important to understand chemical properties?
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Because they determine the changes or transformations that substances may undergo.
Ways in which chemistry has benefitted our lives.
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Technology, health, housing, efficiency, environmentally, sports etc
What do we know about matter?
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Anything that has mass and volume
Mass is a measure of the quantity of matter (kg, g)
Volume is a measure of how big an object is or how much space an object takes up (mL,
L)
Can be solid, liquid or gas or a combination (foam is a liquid and gas)
Changing of State
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Solid to liquid is called melting (0o C)
Liquid to gas is called boiling (vaporization)
Gas to liquid is called condensation
Liquid to solid is called freezing (0o C)
Solid to gas is called sublimation (dry ice)
Gas to solid is called deposition (sub-freezing air, frost)
The Particle Theory
1. All matter is made up of tiny particles
2. All particles have space between them
3. All particles of one substance are the same. Different substances are made of different
particles.
4. The particles are always moving. The more energy the particles have, the faster they move.
5. There are attractive forces between the particles. These forces are stronger when the
particles are closer together.
Particles and Heat
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Little heat equals particles close together, strong attraction, vibrate in place (solid)
More heat allows particles to move slowly, vibrate quicker, less attraction (liquid)
Excessive heat allows particles to break free and separate (gas)
Pure Substances vs Mixtures
pure substance - contains only one kind of particle. For example, a piece of aluminum foil
contains only aluminum particles.
mixture - contains at least two different pure substances. For example; pop
Elements and Compounds
Elements - are pure substances that cannot be broken down into simpler substances.
Compounds - are pure substances that contain two or more different elements in a fixed
proportion.
Atoms - a particle or an element
Molecules - when two or more atoms join together. Molecules can contain two atoms or many
thousands of atoms.
Classifying Mixtures
Solution - a mixture made up of liquids, solids, or gases. Looks like a pure substance. For
example; milk (Homogenous mixture). An alloy is also an example of a solution and is when two
or more metals are mixed together (solder).
Mechanical mixture - a mixture in which each part of the mixture can be seen.
For example; pizza (Heterogeneous mixture)
Suspension - is a cloudy mixture in which tiny particles of one substance are held within
another. Example; Salad dressing (Heterogeneous mixture)
Questions
1. Create a concept map showing how matter can be broken down.
2. What are the two components of matter?
3. Use the particle theory to explain why water changes from a solid to a liquid when it is
heated.
4. Give 3 examples of a pure substance.
5. Give 3 examples of a mixture.
6. Describe a mechanical mixture.
7. Describe a solution.
8. Identify each of the following as a mechanical mixture or a solution.
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a pane of clear glass
chocolate chip ice cream
clear apple juice
a pizza
garbage in a garbage can
9. Classify each of the following as either a pure substance or a mixture.
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pop is composed of water, sugar, and carbon dioxide
carbon dioxide is composed of carbon and oxygen chemically combined
sand is composed of white grains and black grains
graphite at the center of a pencil is composed of carbon
10. Illustrate the difference between a pure substance, a compound and a mixture.
11. Illustrate the difference between a solid, liquid and gas.