Page 30 - General_Knowledge_7
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Tell me how?
What makes the face of a clock glow in the dark ?
The hands and numbers of
the clock are covered with a
special paint, which gives a
small amount of light all the
time. However, in daylight
you can’t see it because the
regular daylight is very bright.
But you can see this glowing
light at night.
Luminous paint glows at night
Luminous paint has special chemicals in
it, so it glows. The chemicals can store up
light and release it too. That’s what causes
the glow you see. But when the paint gets
old those chemicals become weak and
they do not work as well.
On watches too, luminous paint
is often used.
• You can’t see the glow of a
watch that has a luminous dial
in daylight.
• But you will be able to see the
watch glowing dimly in the
dark.
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