We looked at different types of lamp today, including filament lamps, neon & argon lamps, mercury vapour lamps, sodium lamps and fluorescent tube lights.
The wikipedia site has lots of information about different types of light.
See if you can find out how a halogen lamp works.
The envelope of a halogen bulb is made of quartz. This is so it doesn’t melt. The filament is made of tungsten. The envelope is filled with a gas from the halogen group as opposed to argon. If the bulb gets hot enough, the tungsten atoms and the halogen gas combine. This causes tungsten atoms to settle back on the filament. This recycling process means that the bulb lasts longer and is more energy effiecient. You can get more light per one unit of energy. from James R