Chemistry Notes

1
Chemistry Notes
2
What is chemistry?

• Study of matter and its properties

3
Why study chemistry?

• Used in career fields like doctor, nurse,
  pharmacist, engineer, rocket scientist, etc
• Can help you stay healthier helps explain
  reactions in your body and certain diseases and
  their treatments

4
Matter definition

• It has to have 2 things
• Has to have mass and volume

5
How to describe matter?

• Physical Properties - properties you can test
  for or sense without changing the substance
• Examples
• density color taste
• pH magnetism boiling point
• melting point odor

6
Chemical properties

• Chemical properties property in which you test
  how it reacts with another substance, and the
  substance being tested is changed
•  
• Reaction with baking soda
• Flammability
• Decompose with heat

7
State of Matter and Their Properties

• All matter can exist as a gas, solid, or liquid
  at the proper temperature and pressure

8
Solid

• Particles are close to one another and
• dont move
• Fixed shape
• Doesnt fill container necessarily
• High density
• Not very compressible
• Examples steel, copper, plastic, ice

9
Gases

• Particles are far apart and moving fast
• Always fills container
• Takes shape of container
• Least density
• Compressible
• Examples air, natural gas, water vapor

10
Liquid

• Particles can move past each other
• Can fill a container
• Takes shape of a container
• Medium density
• Slightly compressible
• Examples liquid water, milk
•  

11
Two major classifications    Two major
classifications

• Pure substance
• Mixture

12
Two kinds of pure substances

• Element
• Definition pure substance that cant be broken
  down into simpler substances by chemical or
  physical means
•  
•  s approximately 118
•  
• The substances on the periodic table
• Examples gold, iron, hydrogen, oxygen
•  

13
Compound

• Definition pure substance made up of two or
  more different elements chemically combined
•  
• s millions
•  
• Examples salt, water, sugar
•  
•  

14
Mixture

• Mixture two or more pure substances physically
  combined
• Gaseous mixtures like air
• Solid mixtures like alloys such as brass
  and stainless steel
• Liquid mixtures milk, salt water
• Mixtures with more than one phase
• Carbonated beverages
•  

15
Separating or purifying matter

• Mixtures can be separated by physical means
• Separate a mixture of any two pure liquids
• Distillation
• Separate the water in salt water from the salts
• Boil off the water and salts will remain
• Separate a mixture of gases
• Cool them they will condense at different
  temperatures

16
Compounds Can only be separated by chemical
means

• Decomposition Heat to high temperature
• Ex. copper oxide ore from the earth drive off
• the oxygen by heating to a high temperature
• Electrolysis
• Pure water can be separated into hydrogen
  and oxygen gases by using an electric current
•  

17

• Elements
•  
• Cant be purified any further or broken apart by
  chemical or physical means
•  

18
Chemical Changes

• Definition change in which a substance changes
  its chemical identity
• Examples
•  
• Burning propane
• Reaction between vinegar and baking soda
• Also called a chemical reaction

19
Physical changes

•  
• Definition change in which a substance changes
  its physical properties without changing its
  identity.
•  
•   Examples
•  
• Cutting wood
• Tearing up a piece of paper
• Melting ice
• Boiling water
•  
•