Question
Which of these gaseous elements is LEAST reactive? A. hydrogen B. helium C. nitrogen D. oxygen
Answer
4.6
(266 Votes)
Paige
Professional · Tutor for 6 years
Answer
B. helium
Explanation
Reactivity in elements is determined by how readily they combine with other elements. Noble gases are the least reactive due to their complete valence electron shells. Helium is a noble gas with a complete shell, making it extremely stable and inert compared to others.