What you need:
· Colored sidewalk chalk
· Puddle on a paved surface
· A watch
What you do:
1. Find (or create) a puddle of water
on the sidewalk on a sunny day.
Use sidewalk chalk to trace the
outline of the puddle on the side-
2. Make a prediction of what you think will happen to the puddle in one hour.
3. Create two-columns in your notebook. Label the left column TIME and the
right column OBSERVATIONS.
4. Record the time the first puddle was created. Then use a crayon the same
color as the sidewalk chalk outline to draw an illustration of the outline on
the right side of the chart.
5. In one hour, come back for another puddle observation. Use a different
color chalk to trace the new outline puddle. Record the time and, using a
crayon to match the new chalk outline, draw a new illustration of the pud-
dle on the chart. Don't forget to record the information and observation
as accurately as possible. Has the puddle changed? How? Why do you
think the puddle changed?
6. Repeat every hour until the puddle has disappeared.
7. Look over the information on your chart. Explain what you noticed about
the observations you made. Did the shape of the puddle stay the same as
it became smaller? Where do you think the water went?
With the sun's heat, water turns from a liquid to a gas. The water in the pud-
dle turned into tiny droplets of water called water vapor. It evaporated and is
now in the air.