1. Unit 6: Heat

2. What is heat?
Water boils at 100◦ C Lava has an average temperature of 1000◦ C Sparklers burn at 2000◦ C

3. What is heat?
Why would you be severely burned by lava (or even boiling water) but the sparks from the sparkler are harmless?

4. What is heat?
Are there limits to how hot or how cold something can get? Why does a tile floor feel cold while the carpeted floor feels warm at the same temperature? Why does hot air expand by hot water vapor contracts? Why does ice form on the top of the pond, not the bottom?

5. What is heat?
Do you have any questions about heat or temperature?

6. Learning Goal:
I can define temperature and heat and can describe the relationship between them. Based on what you already know, could you: Define heat? Define temperature? Describe how they are alike and how they are different?

7. The Kinetic Theory of Matter
What does kinetic relate to? What is matter? What is a theory?
Kinetic = Motion
Matter = Particles with mass (atoms)
Theory = a scientifically tested idea

8. The Kinetic Theory of Matter
The particles that make up matter are always moving. They have kinetic energy because of their movement. They move in different ways: Straight line (translation) Rotating (Spinning) Vibrating

9. The Kinetic Theory of Matter
Particles can have all three types of kinetic energy (translational, rotational and vibrational) Particles also have potential energy from attractions or repulsions between each other Thermal Energy is the total energy in a particular substance and is thought of as internal energy

10. Temperature
When you hit a nail with a hammer, it becomes warm. Why? When you light a candle in a jar, the jar becomes warm. Why? In each of these examples, the particles gain kinetic energy. In general, the warmer an object, the more kinetic energy its atoms possess.

11. Temperature
Temperature, which is the degree of “hotness” or “coldness” of an object, is proportional to the average translational kinetic energy of the atoms and molecules make up the substance. Temperature is not a measure of the total kinetic energy in a substance.

12. Heat vs. Temperature Heat Temperature Thermal Energy KE + PE
For the whole substance
Measured in calories or joules
Average Translational Kinetic Energy
For each particle in the substance
Measured in degrees

13. Heat vs. Temperature
Example: the Fourth-of-July-type sparkler The sparks that fly from the firework and strike your face have temperatures in excess of 2000°C, but they don’t burn. Because the thermal energy of the sparks is extremely low. Even though the kinetic energy/particle is very high, only a few molecules actually touch your skin.

14. Heat vs. Temperature 1 liter of boiling water
2 liters of boiling water
Temperature? Heat?
Temperature? Heat?
Same
Same
Less
More

15. Reflection
Mark your calendar! Today’s learning goal: I can define temperature and heat and can describe the relationship between them. Using the scale, how do you think you are doing with the concept?