Put these substances in order of density with the most dense first and the least dense last.

air
pumpkin pie
whipped cream
steel

Hello there!

We know that:

This means that two of two objects whit the same size ( volume) the heaviest one is the more dense object.

The 4 that we have here are:

Air, Pumpkin pie, Whipped cream, and Steel

It is easy to assume that the steel is the more dense object.

The pumpkin pie comes second

third is the whipped cream, which is cream with a lot of tiny air bubbles inside

the less dense object is the air.

then the order is:

Steel, pumpkin pie, whipped cream, air.