Answer the question everything is on the screenshot i took.

Concentrations expressed as a percent by mass are useful when the solute is a a. liquid b. gas c. solid

Amolecule is a(n) - a. element that physically combines with another element. b. particle composed of two or more atoms bonded together covalently. c. element that isn't bonded to another element.

Explain how scientific advancements have lessened the effects of hazardous events on society.