Four elements P; Q; R and S have atomic numbers of 4; 10; 12; and 14 respectively. Which of these elements is a noble gas?

Four elements P; Q; R and S have atomic numbers of 4, 10, 12, and 14 respectively. Which of these elements is a noble gas?

A. P
B. Q
C. R
D. S

Correct Answer:

Option B = Q

Explanation

They are the most stable due to having the maximum number of valence electrons their outer shell can hold. Therefore, they rarely react with other elements since they are already stable.