Energy

4 Main Types Kinetic Energy (KE) 1.Energy of motion Potential Energy (PE) 1.Stored energy Chemical Energy 1.Energy associated with a chemical change

4 Main Types Heat Energy 1.Amount of energy transferred from one substance to another − Can be measured using a calorimeter − Calories (cal) or Joules (J) measure heat gain or loss − To convert from cal or J to kcal or kJ divide by 1000

Law of Conservation of Energy Energy is neither created nor destroyed 1.Energy can be transferred from one substance to another 2.Or energy can be transformed into a new form of energy 3.THE TOTAL AMOUNT OF ENERGY WILL REMAIN THE SAME

Law of Conservation of Matter Continued Examples 1.Gas burns in engine (chem to heat) 2.Car moves (mechanical to kinetic)

Thermometry Temperature 1.The measure of the average kinetic energy of the particles of a substance Heat 1.Flows spontaneously from a hot body to a cold body 2.Examples − Body heat to chair − Boiling water to hand − Burned hand to icepack

Thermometry Continued Temperature Scales 1.Degrees Celsius (°C) − Most commonly used scale − Temps below zero are negative − This scale has 2 fixed points (0°C –melting/freezing pt. of water) (100°C – boiling/condensation pt. of water) − Values on thermometer increase by 1°C

Thermometry Continued 2. Kelvin − Contains theoretically the lowest possible temperature 0 Kelvin (absolute zero) − Has never been exactly reached (1/1000 K) − Absence of all kinetic energy (no motion of particles) − Scale is the same as Celsius, just shifted by 273 − 1 degree change in Celsius is the same as 1 degree change in Kelvin − Table T K= °C + 273

Thermometers

A device used to measure the average kinetic energy of particles and temperature Uses liquids like Hg (mercury) and colored alcohols that expand at high temperatures