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Water
from the Sky? - Rainfall  
Raindrops
form in clouds when tiny droplets join together or lager ice crystals
melt. A raindrop must contain as many as 1, 000 droplets for it
to be heavy enough to fall. Then the heavy water droplets fall as
rain
Make a rain detector
of your own. 
Raindrops
and drizzle
Raindrops
are usually about 1.5 mm round. They never grow bigger than 5 mm
which is about the size of a pea. Drops less than 0.5 mm round are
called drizzle. Raindrops are not tear- shaped, as is often thought,
but look like flat- bottomed circles.
Smell
of rain
Many
people claim to be able to smell rain. This may be because our sense
of smell is keener when the air is moist and also because of the
gases given off by wet soil and plants.
How
to measure rainfall?
Rainfall
is measured in millimetres (mm) by rain gauge. Rain gauges measure
the depth of rain, which would cover the ground if none of it drained
away or evaporated. The simplest type is a funnel connected to a
tank, which collects and measures the day's rainfall.
Make a rain gauge of
your own?
Rainbow
A rainbow
is an isolated optical effect caused by the Sun's ray being refracted
(bent) and reflected as they pass through millions of raindrops.
For a rainbow to occur there needs to be bright sunshine and rain
occurring at the same time.
Rainbow effect
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Children
>> Chapters >> Air Moisture>> Precipitation
