What do dust, smoke, salt, and chemicals have in common? a. they are gases in air. b. they make up water vapor in air. c. they are particles in air. d. they are found only in pure air.

The answer is C) because,

Not all of them are gases, only dust and smoke are

They do not all make up water, smoke comes from fire

You can find dust is musky air as well

So the answer is C) They are particles in the air

the dissolution of polymer can be thermodynamically described in 2 steps.

since electrons are negative the answer is neagtaive