2006-06-22 18:46:00 · 12 answers · asked by d s 1 in Education & Reference ➔ Trivia
Older watches were painted with a radioactive isotope, usually radium. The breakdown of the isotope gave off gamma rays that could be seen as a green glow.
Newer watches use tritium (H3) to produce the same effect.
2006-07-04 19:26:21 · answer #1 · answered by jeffma807 4 · 2⤊ 0⤋
well so you can tell time in low light areas, and also because the radium collects energy from light and stores it. and then the stored energy disapates in the form of light in the dark(that green glow.). its just a chymical reaction to light thats all. by the way radium is a rare, brilliant white, luminescent, highly radioactive metallic element found in very small amounts in uranium ores, having 13 isotopes with mass numbers between 213 and 230, of which radium 226 with a half-life of 1,622 years is the most common. It is used in cancer radiotherapy, as a neutron source for some research purposes, and as a constituent of luminescent paints. Atomic number 88; melting point 700°C; boiling point 1,737°C; valence 2. thats all i know about it sorry i dont know more about watches lol.
2006-07-03 12:00:15 · answer #2 · answered by Anonymous · 0⤊ 0⤋
not all watches glow in the dark.
i believe only those made of diamonds, gold, silver or neon materials have a higher chances of glowing the dark.
2006-06-23 01:50:16 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Glow-in-the-dark watches have harmless chemicals that react to create light energy.
2006-07-04 01:41:31 · answer #4 · answered by _anonymous_ 4 · 0⤊ 0⤋
radium material helps watches glow in dark...nothin else
2006-06-23 01:51:14 · answer #5 · answered by d3wanG 2 · 0⤊ 0⤋
they glow due to the radium used in the dial
2006-07-04 15:12:33 · answer #6 · answered by sanjay k 2 · 0⤊ 0⤋
Because most people probably would like to see what time it is even if it is dark.
2006-06-29 22:21:08 · answer #7 · answered by KylieElenstar 3 · 0⤊ 0⤋
BECAUSE ITS CREATED BY GOD TO WACTH PEOPLE IF THEIR DOING A SIN OR A GOOD DEED, IF THEY DO A GOOD DEED, THEIR WILL BE RICH, BUT IF THEY SIN, THEIR WORST NIGHTMARE WILL COME TRUE EXPECT FOR THE END OF THE WORLD.
2006-07-03 16:20:56 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Because sundials don't work at night.
2006-06-30 22:31:12 · answer #9 · answered by therealj5girl 3 · 0⤊ 0⤋
so you can tell the time when the lights are off.
2006-07-02 07:11:08 · answer #10 · answered by duc602 7 · 0⤊ 0⤋