Y9 Science Term 2 Revision Notes (2 of 4)

Law of reflection

Angle of reflection = angle of incidence

Regular reflection

Light is reflected from a smooth surface and produces a clear image.

Diffuse reflection

Light is reflected from a rough surface and does not produce a clear image.

Types of waves

Longitudinal & transverse

Transverse waves

Particles vibrate at right angles to the direction that the wave is travelling.

Longitudinal waves

Particles vibrate in the same direction that the wave is travelling.

Sound travel speed

Sound travels faster through solids because the particles are tightly packed together.

Electron

A particle that has a negative charge (-).

Neutron

A particle that has a neutral charge (/).

Proton

A particle that has a positive charge (+).

Ion

An atom that has lost or gained electrons, affecting its overall charge.

Charge of an atom gaining electrons

It becomes negatively charged.

Charge of an atom losing electrons

It becomes positively charged.

Nucleus of an atom

Contains neutrons & protons.

Neutral atom

An atom that has the same amount of electrons as protons.

Negative atom

An atom that has more electrons than protons.

Positive atom

An atom that has more protons than electrons.

Static electricity

The build up of electric charge on a surface.

Current

The flow of charge.

Electric circuit requirements

An energy source, an energy user/s & wires.

Energy sources for electric circuit

Battery, cell or powerpoint.

Energy users for electric circuit

Light globes, resistors, motors, heating element.