If you are heating something, you can step away for a moment, as long as you come back very quickly. a. True
b. False

b. False

Explanation:

The more energetic molecules move to a gas, spread out, and form bubbles when heating happens. When exposed to heat, many of the chemicals used in the laboratory are volatile and harmful (fire).

So leaving a material that you heat for even a second can be very hazardous and negligent.

Yet both compounds and elements are considered pure substances. Pure compounds are created when elements combine permanently, forming one substance. For example, when the elements mercury and oxygen combine, and a chemical reaction takes place, mercury (II) oxide is created.

Hope this helps!