Grade 10 Optics Review - Key terms

only stuff that I need extra help studying

electromagnetic waves from lowest to highest frequecy

radio, microwave, infrared light, visible, x-rays, gamma rays

Why is an incandescent bulb a very inefficient light source?

Only 5% of the electrical energy converts to light energy, the rest is wasted as thermal energy

Describe the difference between a real image and a virtual image.

Real images are produced when the reflected/refracted rays ACTUALLY meet. Virtual images are produced when the reflected/refracted rays do not meet and our brains imagine the image being created 

Incandescence

Produced by heating a material, mostly a metal filament like tungsten.

Electric Discharge

Light is produced when electricity passes through gas exiting the gas particles and causing them to glow

Phosphorescence

Materials absorb light energy and slowly release it over time as visible light.

Fluorescence

• Produced when light is absorbed and almost immediately re-emitted.

• When a molecule relaxes to a lower energy state through emission of a photon.

Chemiluminescence

Chemiluminescence is light produced from a chemical reaction.

Bioluminescence

Chemical reaction within a living creature.

When a molecule called luciferin reacts with an enzyme called luciferase

LED

LEDs produce light using a process called electroluminescence (the process where material emits light).

Triboluminescence

When a material is mechanically stressed through stretching, rubbing or crushing

Fusion

2 light nuclei merging into one larger nucleus. Usually UV light

What is refraction/why does it happen?

the bending of a wave, like light, as it passes from one medium to another. This bending occurs because the wave's speed changes as it enters the new medium.

If medium 2 is more dense than medium 1, refracted ray bends…

towards the normal

if medium 2 is less dense than medium 1, refracted ray bends…

away from the normal