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

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

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

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

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.

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

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

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

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

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

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.

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