Question

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

Answer 1

Answer: (C)

it has a completely filled $d$-orbital that prevents $d-d$ overlapping of orbitals

Answer 2

The electronic configuration of mercury $(80)$ is, $[Xe] 4\int^{10}, 5d^{10}, 6s^2$. 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.