1. How are various forms of energy different?

2. Energy is defined as the ability to do work.
Types of energy include:
Chemical
Electrical
Electromagnetic
Thermal
Mechanical
Nuclear

3. Law of Conservation of Energy:
The total amount of energy in a system is constant.
Energy can be neither created nor destroyed, but it can be converted from one form to another.
In a closed system, mass, charge, and energy are conserved (can neither be created nor destoyed)

4. Potential Energy (PE) is related to position:
When bodies that attract each other are far apart, they have HIGH PE.
When bodies that attract each other are close together, they have LOW PE.
In which phase of matter do particles have the least PE?

5. Chemical Potential Energy:
Chemical bonds store PE
STRONGER bonds have GREATER STABILITY.
WEAKER bonds have LESS STABILITY.
***When a bond is FORMED, energy is RELEASED
***Energy must be ABSORBED when a bond is broken.

6. Kinetic Energy (KE) is associated with motion.
The faster an object moves, the more KE the object has.
**Temperature is a measure of average kinetic energy.
Temperature is measured in degrees Celsius (°C) and kelvin (K)
The Kelvin Scale is based on Absolute Zero, so there are no negative kelvin temperature values
Conversion: K = °C + 273

7. Heat and Temperature are NOT the same!
Heat is energy that is transferred between objects because of temperature differences between them
Heat energy flows from a hotter object to a colder one (until the temperature of both is the same)
The amount of heat transferred depends upon mass
Temperature is a measure of average KE and is independent of mass

8. Chemical and physical often either absorb or release energy.
An endothermic process absorbs or requires energy from its surroundings
The surrounding temperature decreases
An exothermic process releases energy into its surroundings
The surrounding temperature increases

9. Phase Changes are Endothermic or Exothermic

10. Heating Curve and Cooling Curves
Heating and Cooling Curves help to describe the energy changes that accompany the phase changes

11. Heat Equations Use the Heat Equations to solve problems asking for:
how much heat is required or released…
how many grams or what mass can be heated
what will be the temperature change, the final temperature, or what was the initial temperature

12. Heat Equations
q = mCΔT
C (specific heat capacity) of liquid water is J/g K or 4.18 J/g°C
Use this equation when there is a change in temperature
Ex. How much heat is required to raise the temperature of 35.0g of water from 25.0°C to 37.0°C?

13. Heat Equations q = mHf Hf (heat of fusion) of water is 334 J/g
Use this equation when asked how much heat is required to melt or is released when … freezes
Ex. How much heat is released when 5.25g of water freezes at 0°C?

14. Heat Equations q = mHv Hv (heat of vaporization) of water is 2260 J/g
Use this equation when asked how much heat is required to boil or is released when … condenses
Ex. What mass can be boiled (can be evaporated) when a large sample of water at 100°C absorbs 12.4kJ of heat?