Q. The number of electrons and protons in an atoms of third alkaline earth metal is
A) $e\ 20,\ p\ 20$
B) $e\ 18,\ p\ 20$
C) $e\ 18,\ p\ 18$
D) $e\ 19,\ p\ 20$
Explanation
(a)
The third alkaline metal is $\ _{20}^{40}Ca$. It contains 20 protons and 20 electrons.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.