Help me out please !!

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.

Which scenario is most similar to the type of collision that gas particles have according to kinetic molecular theory

In which of the following phases of matter do molecules have the highest amount of energy? a. liquid b. gel c. solid d. gas