Imagine you're at a hot air balloon event. The balloonists are busy preparing
for flight. They spread out the enormous balloons on the grass and check all
the lines. The talk is all about today's temperature, wind speed, and
direction. Some of the balloonists have turned on their gas burners and point
them into the open end of the balloon. You tilt your head back to watch them
lift off the ground and fill the sky with a rainbow of colors.
They're floating away. Floating away? But how? Did you ever wonder why hot air
You may already have some ideas. Think about them and then choose one of the
options below that seems closest to why you think balloons float.