BGS - 07. Energy

Question 1

Energy

Energy can be converted from one form to another, but cannot be destroyed

Known as Law of Conservation Energy

Answer 1

i.e. if 100j of energy goes in,
100j of energy must come out

2

Question 2

Transfer of heat energy

3 main types

Conduction
Convection
Radiation

Answer 2

Conduction
Heat moves through a substance. i.e. a teaspoon in a hot cup of water will get hot as heat is passed through it
Convection
When a fluid (gas or liquid) moves under the influence of heat. i.e. hot air rises, taking heat with it
Radiation
Particles behave as waves rather than individual particles

3

Question 3

Infrared Radiation

All objects emit and absorb infrared radiation.

The hotter the object, the more it radiates

Answer 3

Dark matt surfaces are good heat absorbers

Light shiney objects are less efficient heat absorbers

4

Question 4

Kinetic Particle Theory

Particles in solids, liquids and gases have different amounts of energy. They are arranged differently and move in different ways

Answer 4

Table explains the way particles behave

TABLE

5

Question 5

Conduction

Objects good at conducting heat energy are called conductors

Objects not good at conducting heat energy are called insulators

Answer 5

6

Question 6

Convection

As particles in liquids and gasses are heated, they move faster and the gaps between them widen. The gas or liquid therefore expands, making them less dense.

Answer 6

7

Question 7

Evaporation and Condensation

Evaporation = Liquid into Gas
Condensation = Gas into liquid

Answer 7

Taking high energy level particles out of a liquid means the remaining particles have less energy. Subsequently, this means the remaining liquid cools down.

This is how sweating works.

Similarly, particles in a gas have different energy levels. Particles that have insufficient energy to remain as a gas turn back into liquid (condense).
Particles bond, releasing some of their energy.
The energy remains in the gaseous particles, thus raising tehir temperature

8