BOY: That's Carla, me and ISABEL, and we are drawing.
CARLA: We are drawing with chalk.
Let's try adding water to the chalk.
Whoa!
If you add some water, it gets more of a dark color.
GIRL: That is cool!
CARLA: We took a break from our sidewalk chalk
We're playing with airplanes now.
3, 2, 1!
BOY: While we were gone,
the hot, hot sun was drying out the water.
Here's what it looks like speeded up.
The chalk is now all dry again.
ISABEL: It was wet, but now it's dry.
CARLA: The water kind of like went up,
and the chalk got left here.
Let's try painting just with water.
If you paint on the sidewalk with water,
it's just going to go away.
BOY: Here's what it looks like really speeded up.
ISABEL: There was a shape there; some of it evaporated.
BOY: Evaporating is when there's water on the ground,
it turns into steam you can't see.
ISABEL: The water turns into clouds in the sky.
CARLA: Some day it will fall out as rain.
BOY: Try painting with water and see how the water disappears.