1. Energy & Heat notes

2. Energy Energy is the ability to do work Energy exists in many different forms Can you think of any? Kinetic Energy Potential Energy Chemical Energy Thermal Energy Nuclear Energy Sound Energy Light Energy Law of Conservation of Energy- energy cannot be created or destroyed, it simply changes forms

3. Chemical Energy Energy within matter due to its chemical makeup. Chemical reactions convert chemical energy to other forms of energy (light, heat, etc.) Examples? Batteries Food

4. Kinetic Energy Energy of motion How is this different from potential energy? Particles (atoms) are always in motion. They have kinetic energy

5. Heat Heat is the sum of the kinetic energy of the particles in a sample Temperature is the measurement of heat. Temperature is a measure of the average kinetic energy of the particles in a sample http://intro.chem.okstate.edu/1314F00/Laboratory/GLP.htm http://intro.chem.okstate.edu/1314F00/Laboratory/GLP.htm Watch what happens to the particles as the temperature is increased

6. Endothermic & Exothermic An exothermic reaction feels hotter because heat is exiting the reaction. Heat is moving from the system (the reaction) to the surroundings (your hand) An endothermic reaction feels colder because heat is entering the reaction. Heat is moving from the surroundings (your hand) to the system (the reaction) THERE IS NO SUCH THING AS COLD IN SCIENCE CLASS!!! ONLY HEAT CAN MOVE!

7. How would you convert from Celsius to Kelvin??

8. Specific Heat Capacity The amount of heat energy required to raise the temperature of 1 g of a substance by 1 ºC. The specific heat of water is 1.00 cal / g ºC 1000 cal = 1 Calorie (from your nutrition labels) The specific heat of water is 4.184 J/ g ºC Both Jules (J) and calories (cal) are units of energy

9. Comparing Heat Capacities Given: The heat capacity of water is 4.184 J/g ºC The heat capacity of copper is 0.385 J/g ºC Which one requires more Jules to raise the temperature of 1 gram 1 ºC ? Does this mean that water feels hotter faster or slower than copper?

10. Energy and Temperature During a Phase Change As energy is increasing what is happening to temperature? (blue) Why might energy increase but temperature stay constant? (green)