Can you please help me with 1-3

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.

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?

May someone me with these science questions