Luminescence is emission of light by certain materials when they are relatively ... .

Where can you not see luminescence?

• incandencent lamps

• glowworms

• lightning

• fluorescent lamps

The first investigations of luminescence began with ...

• an organic material

• a polymer

• a synthetic material

• an inorganic material

Today, the name ... is used for the chemical element only.

Zinc sulfide is...

• a phosphor

• phosphorus

Luminescence emission ... after an appropriate material has absorbed energy from a source such as ultraviolet or X-ray radiation, electron beams, chemical reactions, and so on.

The absorbed energy is liberated in the form of …

• ultraviolet radiation

• nuclear energy

• light or heat or both

• X-ray radiation

Phosphorescence means light emission caused by electronic transitions between levels of ... multiplicity.

Fluorescence is used for light emission connected with electronic transitions between levels of ... multiplicity.

The name luminescence has been accepted for all light emitting phenomena not caused by a rise of ... .