In which group on the Periodic Table would a nonmetallic element belong if atoms of this element ten

January 2018 NY Regents Chemistry Exam

34 In which group on the Periodic Table would a nonmetallic element belong if atoms of this element tend to gain two electrons to complete their valence shell?

(1) 14

(2) 15 (3) 16

(4) 17

Solution: If atoms want to gain 2 electrons to complete their valence shell, we are looking for an element with -2 oxidation number (gaining two electrons is gaining two minus charges). We can look at the Periodic Table to see the oxidation numbers. on the top right corner of each element.

Answer: 3