Answer
a. alkali metal;
b. halogen;
c. alkaline earth metal;
d. alkaline earth metal;
e. noble gas
Work Step by Step
a. Sodium is in the 1A group; therefore, sodium is an alkali metal.
b. Iodine is in the 7A group; therefore, iodine is a halogen.
c. Calcium is in the 2A group; therefore, calcium is an alkaline earth metal.
d. Barium is in the 2A group; therefore, barium is an alkaline earth metal.
e. Krypton is in the 8A group; therefore, krypton is a noble gas.
