Waves
Science

A wave whose particles vibrate parallel to the direction in which the wave travels
Longitudinal wave
A wave whose particles vibrate parallel to the direction in which the wave travels. Longitudinal wave. In a longitudinal wave, particles move back and forth in the same direction as the wave travels, like sound waves in the air.

The bending of light when it passes from one substance into another
Refraction
The bending of light when it passes from one substance into another. Refraction. Refraction is when light changes direction as it moves from one material to another, like air to water, causing objects to look bent or distorted.

An increase in the vibration amplitude of an object, caused by another object vibrating at the same frequency
Resonance
An increase in the vibration amplitude of an object, caused by another object vibrating at the same frequency. Resonance occurs when an object vibrates at the same natural frequency as another, causing it to vibrate more strongly.

A wave that seems stationary, it forms when two waves of equal wavelength and amplitude cancel each other out
Standing wave
A wave that seems stationary, it forms when two waves of equal wavelength and amplitude cancel each other out. Standing wave. In simple terms, a standing wave is a pattern created when two identical waves pass through each other, appearing to stand still.

A wave that moves particles of matter at right angles to its direction of travel
Transverse wave
A wave that moves particles of matter at right angles to its direction of travel. Transverse wave. A transverse wave is like a sideways ripple, where energy moves forward while particles vibrate up and down.