3. Incandescent Light
Incandescent light: when an object is heated to such a high
temperature that it emits visible light.
Example: candle flames and light bulbs
Note: 95 percent of the energy given off by incandescent light bulbs
is released as heat. That's why light bulbs are hot! In a way, an
incandescent source of light is like having a small electric heater in
the room.
4. Fluorescent Light
Fluorescent Light: Invisible ultraviolet light is
absorbed by the particles. These particles then
glow and emit light we can see (visible light).
In a fluorescent light tube an electric current from
the wires causes the mercury vapour inside the
tube to give off ultraviolet radiation. A phosphor
coating on the inside of the tube absorbs the
ultraviolet energy. This causes the coating to
glow, thus producing light that you can see.
Example: ‘Black light’, fluorescent light tubes
5. Fluorescent Light
Advantages:
• Don’t get as hot as incandescent lights
• They lose less energy and are energy efficient
Disadvantages:
• More expensive
• Harder to dispose of
• Chemicals inside can be toxic
6. Phosphorescent Light
Phosphorescent Light: similar to a
fluorescent source. Light energy is
absorbed by certain particles that can
store this energy for a while. The stored
energy is later released as visible light.
Example: Anything that has that green
glow in the dark color to it. Glow in the
dark star stickers you can put on your
ceiling.
7. Fluorescent vs. Phosphorescent Light
• Particles in the fluorescent source release their light energy
immediately. Phosphorescent particles take longer to emit light.
• Phosphorescent light also continues to glow for a while after the
energy source has been removed
8. Chemiluminescent Light
Chemiluminescent Light: When a
chemical reaction produces
energetic particles that give off
visible light energy.
Example: Glow sticks (The
chemicals inside the tube when you
crack it react and glow)
9. Bioluminescent Light
Bioluminescent Light: Chemical
reactions that happen inside living
creates to create a glowing
chemical
Example: Creatures at the bottom
of the ocean (The angular fish that
attacks dory in finding nemo)
