Q. Mercury is a liquid metal because
A) It has a completely filled $s$-orbital.
B) It has a small atomic size.
C) It has a completely filled $d$-orbital that prevents $d - d$ overlapping of orbitals.
D) It has a completely filled $d$- orbital that causes $d - d$ overlapping.
Explanation
(c)
The electronic configuration of mercury (80) is [Xe]$4f^{10},\ 5d^{10},6s^{2}$. Its $d$-subshell is completely filled, thus it prevents the overlapping of $d$-orbitals ($d - d$ overlapping).
Hence, it is liquid metal at room temperature.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.