William Ramsay 1852-1916
Atomic number 36 * Krypton Kr. * Atomic weight 83.8
is obtained by fractional distillation of liquid air. Krypton is an inert
gas and occurs in the air. It is used to fill vacuum tubes and light
bulbs. Krypton is a chemical element and was discovered by the British chemist Sir William Ramsay in
1898. Ramsay discovered five of the noble gases. He extracted samples of most of
the gases of air. He named them argon (from the Greek word for inactive),
neon (new), xenon (stranger) and krypton (hidden). Helium (Sun) had been
detected in the Sun's spectrum.
The noble gases are the elements that form group O of the periodic table. The six noble gases are so inert, or stable, that they rarely react with other materials. In chemistry, -noble- means unreactive. The noble gases have no smell, colour, taste and do not burn. The noble gases are, in order of lightest to heaviest: helium, neon, argon, krypton, xenon and radon. Radon is the heaviest of the noble gases, is radioactive and can cause lung cancer if inhaled in large enough quantities.
Glass tubes filled with gases that produce coloured light are used in decorative lighting for shops, advertising or party-lights in the home. Neon and other noble gases, such as argon and krypton are used for this. Coloured lighting is not really suitable for the home or work where white light is needed.
Materials needed: Lamp and several coloured light bulbs. (red - yellow - blue - green - orange)
What to do: Sit in a dark room (preferably at night) and switch on the coloured light. Try to read a book in this light. Only read for a few seconds at the time and write down on a scale from 1 - 10 the difficulty level at reading using the coloured light. Repeat the same procedure swapping the coloured light bulbs.
|Reading Difficulty Level
on a scale from 1 - 10
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