During which phase change do water molecules form crystal lattice? . a. melting. b. freezing. c. boiling. d. condensing.

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

The rules of engagement (roe) working group is often used to (select all that apply.)

How many atomic mass units are equal to 1.672×10−24 g of protons?