Activity Books Understanding Water Activity Book | Page 39

Water to be cleaned is brought to a treatment plant.
It flows into a container. Heavy particles settle to the
bottom of the container.
There are fine particles that don’t settle to the
bottom of the container. These particles need to become
heavy enough to sink. Coagulation is the process of
combining small particles with other small particles to
create larger solids. Alum, a chemical which makes the
particles stick together, is added to the water. The water
is mixed with rotating mixers at high speed.
It is easier to remove big things from water than tiny
things. If you can make the little things in water stick
together or make them heavier than water so they sink,
it will be easier to gather them together.
1
Which of the groups of paper clips will be easier
to remove from the water?
2
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