Year 8 Energy Test - Key Concepts and Vocabulary

Vocabulary flashcards covering energy forms, conservation, transfer methods, and efficiency from the Year 8 Energy topic.

Energy

The entity required for objects to move, measured in joules.

Kinetic energy

Energy of motion.

Mechanical energy

Energy due to motion of an object.

Thermal (heat) energy

Energy due to vibration or movement of particles.

Sound energy

Energy due to vibration transferred through matter in waves.

Electrical energy

Energy due to the flow of charged particles.

Radiant (light) energy

Electromagnetic energy that travels in waves that we can see.

Potential energy

Stored energy.

Chemical energy

Energy stored in the bonds between atoms.

Nuclear energy

Energy stored in the nuclei of atoms.

Gravitational energy

Energy stored in an object's height.

Elastic energy

Energy stored in stretched objects.

Joules

The unit used to measure energy; convertible to kilojoules and megajoules.

Law of Conservation of Energy

A scientific law stating that energy can neither be created nor destroyed, and can only be converted from one form of energy to another.

Energy transformation

Changing energy from one type to another type.

Energy transfer

Moving energy of the one object to another object.

Percentage efficiency

Percentage efficiency = useful energy output (J) total energy input (J) × 100 Percentage efficiency= total energy input (J) useful energy output (J) ​ ×100 Percentage efficiency=useful energy output (J)total energy input (J)×100Percentage efficiency=total energy input (J)useful energy output (J)​×100

Conduction

Heat transfer due to objects touching each other.

Convection

Heat transfer due to the movement of fluids.

Radiation

Heat transfer due to the emission of infrared electromagnetic waves; it is invisible to the eye, not affected by air flow, and can travel in the vacuum of space.

Conductors

Objects that easily transfer thermal energy.

Insulators

Objects that slow the transfer of thermal energy.

Convection currents

Fluid circulation caused because hot fluids (liquids and gases) are less dense and rise up, and cold fluids are more dense and sink.