Warm Up October 7, 2013 Sarah’s Lab group is investigating heat energy. They take two thermometers and place one on the table and one inside a mitten. They check the thermometers an hour later. The temperature inside the room stayed the same the whole time. What do you think they will find? a.The thermometer inside the glove will have a lower temperature reading. b.The thermometer on the table will have a lower temperature reading. c.Both thermometers will have the same reading. Explain why you chose your answer.

Correct HW p. 72

Section 2.3 Energy and Matter Energy: the ability to move or change matter Law of Conservation of Energy: – Energy cannot be created or destroyed but can change forms Energy changes occur when chemical and physical changes take place.

Forms of Energy The following forms of energy are related to changes in matter: – Electrical Energy – Chemical Energy – Electromagnetic Energy – Thermal Energy

Electrical Energy Energy of moving electrical charges

Electromagnetic Energy Energy that travels though space as waves

Chemical Energy Energy stored in chemical bonds holding atoms together in molecules. Energy is stored in the chemical bonds

Thermal Energy Also know as HEAT. Thermal energy is the sum of all motion of all the particles (atoms or molecules) in a sample of matter. Less thermal energy More thermal energy

Temperature Temperature is a measure of the average speed of particles in a sample of matter.

What’s the Difference? Suppose you make some hot chocolate and a drop falls on the counter. Temperature = 100°C Speed of one particle: 1500 mph Less thermal energy/heat because there are less particles moving at this speed More thermal energy/heat because there are more particles moving at this speed

There is no such thing as “cold” in science. There is only matter that has more heat/thermal energy and matter that has less heat/thermal energy. Heat always flows from areas with more heat to areas with less heat. More Heat  Less Heat

Endothermic Changes Endothermic changes require heat/thermal energy to occur. “in” “heat”

Exothermic Changes Exothermic changes lose or release heat/thermal energy as they occur. “exit” “heat”

Comparing Energy Changes Worksheet

Cool Down Title: Endothermic vs. Exothermic Double Bubble Map

Homework P. 77 # 1a-c, #2a-c Finish “Comparing Energy Changes” Worksheet Vocab Booklet: Temperature, Thermal Energy, Endothermic Change, Exothermic Change Quiz Wednesday: Identify 10 chemical equations (just like the worksheet) as endothermic/exothermic and chemical/physical.