Q. Which pair has both members from the same period of Periodic Table?
A) Cl, Br
B) Ca, Cl
C) Na, Ca
D) Na, Cl
Explanation
(d)
Sodium and chlorine are in same period
$_{11}Na = 2,\ 8,\ 1$
$\ _{17}Cl = 2,\ 8,\ 7$
Both have 3- shells, hence they both are placed in 3rd period of Periodic Table.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.