1. Thermal Energy Temperature & Heat 1. Temperature is related to the average kinetic energy of the particles in a substance.

2. 2. SI unit for temp. is the Kelvin a. K = C + 273 (10C = 283K) b. C = K – 273 (10K = -263C) 3. Thermal Energy – the total of all the kinetic and potential energy of all the particles in a substance.

3. 4. Heat a. The flow of thermal energy from one object to another. b. Heat always flows from warmer to cooler objects. Ice gets warmer while hand gets cooler Cup gets cooler while hand gets warmer

4. 5. Specific Heat a. Some things heat up or cool down faster than others. Land heats up and cools down faster than water

5. b. Specific heat is the amount of heat required to raise the temperature of 1 kg of a material by one degree (C or K). 1) C water = 4.184 J / g C 2) C sand = 0.290 J / g C This is why land heats up quickly during the day and cools quickly at night and why water takes longer.

6. How to calculate changes in thermal energy Q = m x  T x C p Q = change in thermal energy m = mass of substance  T = change in temperature (T f – T i ) C p = specific heat of substance

7. Example 1 What amount of heat energy is required to raise 20g of water by 30°C? Specific heat of water is 4.184 J/g x o C

8. Example 2 A sample of water requires 4000 joules to raise the temperature 20 o C. What is the mass of this sample?

9. Example 3 A 83.7g sample of nickel absorbs 483 J of energy when the temperature increases from 13.8 o C to 56.8 o C. What is the specific heat of nickel?

10. Example 4 What increase in temperature will result if 412.0 g of copper absorbs 4.08 kJ of heat energy? C Cu = 0.385 J/g o C