PLEASE ANSWER ASAP NEED ANSWER 75 POINTS Which statement about pure substances and molecules is correct?

A. Pure substances cannot be molecules.

B. All molecules are pure substances.

C. Molecules cannot be pure substances.

D. All pure substances are molecules.

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Match the following items. 1. high-intensity bundle of energy being emitted from some decaying nuclei gamma ray 2. particle radiating from the nucleus of some atoms beta particle 3. negative particle identical to an electron but radiating from a decaying nucleus alpha particle

Identify the electromagnets with poles that are reversed from the electromagnet shown above