Which element has the lowest first ionization energy?
Be
Sr
OCa
Mg

Energy is released during which phase changes? check all that apply. boiling condensing depositing freezing melting subliming

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?

What is a substance? a. a physical property of matter b. a chemical property of matter c. an element or compound that cannot be physically separated d. characteristics used to tell the difference between mixtures