The video is being made. Until it arrives, here is what it will say (117 words, about 58 seconds):

Here's Miss Mendez's class, camping at a state park. As the sun sets, she strikes a match and lights the campfire.

The match burns down to a black, crumbly stick, and smoke drifts up.

Frankie opens the cooler. The ice she packed this morning has turned into cold water.

Gabriel says the match and the ice both changed. So are those two changes the same kind, or two different kinds?

To find out, we will look at ice, water and water vapor, at changes that make a new material or keep the same material, and at the clue that tells them apart.

Okay, so are you ready to find out when a change makes a new material?

It ends with a ready line. Then pick a reply below — any reply counts.