Sodium forms the compounds Na2S, Na3N, and NaHCO3. What are the formulas for lithium sulfide, lithium nitride, and lithium hydrogen carbonate? Consider the element magnesium. Which statement is true? (11.4)
(a) It is in Group 5A.
(b) It is a noble gas.
(c) A magnesium atom has electrons in nine shells.
(d) It is an alkaline earth metal.