Unit 2 Lesson 3

Question 1

Thermal Energy

Answer 1

The total kinetic energy of all particles in a substance

Measured in Joules (J)

The number of molecules in a substance and the temperature determines thermal energy

Question 2

Temperature

Answer 2

A measure of the average kinetic energy of all the particles in a substance

Question 3

Heat

Answer 3

The thermal energy transferred from an object at higher temperature to an object at lower temperature

Energy is always transferred from hot to cold

Heat is measured in calories (cal) and Joules(J)

Question 4

Calorie

Answer 4

The amount of energy needed to raise the temperature of 1gm of water by 1 degree C

Question 5

Conduction

Answer 5

The transfer of energy as heat from one substance to another through direct contact

Question 6

Conductor

Answer 6

A material that transfers heat very well
Example: metals

Question 7

Insulator

Answer 7

A material that does not transfer heat well
Example: wood, paper, plastic foam

Question 8

Convection

Answer 8

The transfer of energy as heat by the movement of a liquid or gas.
It occurs when a cooler, denser mass of a gas or liquid replaces a warmer less dense mass of a liquid or gas by pushing it upwards

Question 9

Radiation

Answer 9

The transfer of energy by electromagnetic waves such as microwave, infrared light

Differs from conduction and convection because radiation can travel through empty space. Conduction and convection cannot

Question 10

Convection Current

Answer 10

The circular motion due to density differences that result from temperature differences