1. Chemistry

2. What is Chemistry?
The study of all substances and the changes they undergo.
Called the central science because it overlaps many other sciences.
Chemistry explains underlying reason things happen in our world.

3. Branches of Chemistry
Organic – study of most carbon containing compounds
Inorganic – study of non-organic substances, may have organic fragments bonded to metals
Physical – study of properties, changes, and relationships between energy and matter
Analytical – study of components and composition of materials
Biochemistry – study of substances and processes occurring in living things
Theoretical – use of math and computers to design and predict the properties of new compounds
Give examples of each of the branches and some applications of each branch

4. Types of Chemical Research
Basic Research – for the sake of increasing knowledge
Applied Research – to solve a specific problem
Technological Development – the production and use of products that improve our quality of life (lag behind discovery)

5. States of Matter Solid- fixed volume and shape
Particles are in a rigid structure vibrating slightly in place
high density
Liquid- fixed volume but no fixed shape
Particles move past each other
Takes shape of container
Allows liquid to flow
Lower density
Gas- no fixed volume or shape
Expand to fit container
Lots of space between particles
Low density-also compressible
Plasma
Properties like gas
Ionized gas
More energy than gas

6. Properties Characteristics of matter
Extensive properties depend on the amount of matter present
mass, volume, energy
Intensive properties do not depend on the amount of matter present
melting point, boiling point, density

7. Other Categories of Properties
Chemical –ability to undergo changes that transform it into different substances
Examples: combustion (burn), oxidation (rust), corrosion, decomposition
Physical- describe characteristics of that substance that can be measured or observed without changing the substance
melting and boiling point, density, specific heat

8. Physical Changes Do NOT change the identity of the substance
grinding, tearing, changing shape
State changes are always physical changes
Melting- solid to liquid
Evaporation- liquid to gas
Condensation- gas to liquid
Sublimation- solid to gas
Freezing- liquid to solid
Deposition- gas to solid

9. Chemical Changes Change the identity of a substance
Seen when 2 substances react to form a new substance
Chemical equations describe chemical changes (chemical reactions)
Ex – 2Na + Cl2 → 2NaCl
Items on left are reactants (what you begin with)
Items on right are products (what you end with)

10. Evidence of Chemical Change
Formation of Gas
Often you see gas, smoke, or bubbles
Formation of precipitate
You see a new solid in a liquid
Release or absorption of heat or light
You feel it get hot or cold
Color changes
Odor change

11. Evidence of Chemical Change