Question

Which of the following is NOT true about chlorine? A. It is not reactive. B. It combines with sodium to form table salt. C. It is a poisonous, greenish gas. D. It was used in battles in World War I.

Answer 1

None of the possible answers you gave are wrong. 

Answer 2

Chlorine is a chemical element with symbol Cl and atomic number 17 that is widely used in the chemical and pharmaceutical industry. It is a toxic, corrosive, greenish yellow gas, irritating to the eyes and skin.
It is denoted as Cl.
The following statement is NOT true about chlorine: A. It is not reactive.