Science Energy revision for test

What is energy?

Energy is the ability to do work or cause change.

What is the unit of energy?

Joules (J).

What is kinetic energy?

Energy an object has because it is moving.

What is potential energy?

Stored energy due to an object's position, shape or condition.

Which energy types are kinetic?

Electrical, thermal, sound and light.

Which energy types are potential?

Gravitational, chemical, nuclear and elastic.

What is electrical energy?

Energy from moving electric charges. Example: electricity in a circuit.

What is thermal energy?

Energy from moving particles. Example: a hot cup of tea.

What is sound energy?

Energy carried by vibrations. Example: a speaker.

What is light energy?

Energy carried by light. Example: sunlight.

What is gravitational energy?

Stored energy because of height. Example: a book on a shelf.

What is chemical energy?

Energy stored in chemical bonds. Example: food, fuel or batteries.

What is nuclear energy?

Energy stored in the nucleus of an atom. Example: the Sun.

What is elastic energy?

Stored energy when something is stretched or squashed. Example: a rubber band.

What is an energy transfer?

Energy moving from one object or place to another.

Give an example of an energy transfer.

Heat moving from a hot drink to your hands.

What is an energy transformation?

Energy changing from one form to another.

Give an example of an energy transformation.

Chemical energy → kinetic energy when you move.

What is the Law of Conservation of Energy?

Energy cannot be created or destroyed. It can only be transferred or transformed.

What happens to the total amount of energy?

It always stays the same.

What is a flow diagram used for?

To show energy changing from one form to another.

What is the energy change in a light bulb?

Electrical energy → light energy + thermal energy.

What is the energy change in a car?

Chemical energy → kinetic energy + thermal energy + sound energy.

What is the energy change in a solar panel?

Light energy → electrical energy.

What is input energy?

The energy put into a system.

What is output energy?

The energy that comes out of a system.

What is useful energy?

The wanted output energy.

What is waste energy?

Unwanted energy that is not useful.

What are the energy changes in a light bulb?

Input: electrical energy. Useful: light energy. Waste: thermal energy.

What is the particle model?

The idea that all matter is made of tiny particles.

What are particles like in a solid?

Close together and vibrating in fixed positions.

What are particles like in a liquid?

Close together but able to move past each other.

What are particles like in a gas?

Far apart and moving freely.

What is temperature?

A measure of how hot or cold something is.

What is thermal energy?

The total energy of all the particles in an object.

What is heat?

Thermal energy moving from a hotter object to a colder object.

What is the difference between temperature and thermal energy?

Temperature measures how hot something is. Thermal energy is the total energy of all its particles.

What does thermal energy depend on?

Mass, temperature and material.

How does mass affect thermal energy?

More mass means more particles and more thermal energy.

How does temperature affect thermal energy?

Higher temperature means faster particles and more thermal energy.

How does material affect thermal energy?

Different materials can store different amounts of thermal energy.

What is conduction?

Heat transfer through direct contact.

How does conduction work?

Fast-moving particles pass energy to nearby particles.

Give an example of conduction.

A metal spoon getting hot in tea.

Where does conduction work best?

In solids, especially metals.

What is convection?

Heat transfer by the movement of liquids or gases.

How does convection work?

Warm fluid rises and cool fluid sinks, creating a convection current.

Give an example of convection.

Boiling water.

What is radiation?

Heat transfer through electromagnetic waves.

Does radiation need particles?

No. It can travel through empty space.

Give an example of radiation.

Heat from the Sun.

What is the difference between conduction, convection and radiation?

Conduction = contact. Convection = moving liquids or gases. Radiation = electromagnetic waves.

How can I remember the 3 types of heat transfer?

Conduction = Contact. Convection = Currents. Radiation = Rays.