1. Unit 7 Chapter 2 & 3 Matter cont.
P. Sci.
Unit 7
Chapter 2 & 3
Matter cont.

2. How Formulas are Written
Write the chemical symbols for each element contained in the substance.
Place the number of atoms of each element as a subscript behind the element’s symbol
No subscript for one atom – the symbol shows that there is at least one atom there

3. H2O H = hydrogen O = oxygen
For every one atom of oxygen there are two atoms of Hydrogen

4. Matter and Energy Kinetic Theory of matter:
1. All matter is made of atoms and molecules that act like tiny particles

5. 2. These tiny particles are always in motion
2. These tiny particles are always in motion. The higher the temperature, the faster the particles move.

6. 3. At the same temperature, more massive (heavier) particles move slower than less massive (lighter) particles.

7. States (phases) of Matter
Solid – definite volume; definite shape; fixed positions
Liquid – definite volume; no definite shape; can move around and in between each other

8. States (phases) cont.
Gas – no definite volume; no definite shape; random straight- line paths.
Plasma – gas-like substance of charged particles; traveling very fast

9. Phase change and Thermodynamics
Solids – low energy – little movement.
Liquids – higher energy – more movement.
Gases – highest energy – the most movement.

10. Energy and Phase Change
Energy is transferred in all changes of state.
Solid ↔ Liquid ↔ Gas
Sublimation – change from solid to gas without becoming a liquid

11. Law of Conservation of :
Mass – Mass cannot be created nor destroyed it can only be changed.
Energy – Energy cannot be created nor destroyed it can only be changed.

12. P T V Gas Laws Charles’ Law – Boyles’ Law – Lussac’s Law – Charles’
pressure
Temp.
Volume