WAEC - Chemistry (2000 - No. 1)
The atoms of four elements are represented as 20Q, 16R, 10S and 8T Which of the elements would be unreactive?
Q
R
S
T
Erläuterung
Element S has an atomic number of 10, which means it belongs to Group O. Recall that elements in group O are inert gases (Unreactive) as they have completely filled electrons in their outermost shell. However, no other element in the option has its outermost shell electrons completely filled. The correct answer is option C