Read the following passage and answer the next five questions based on it.
The transition metals are very hard and have low volatility. Their melting and boiling points are high. In any row, the melting points of these metals rise to a maximum at d5 and fall regularly as atomic number increases. The high melting points of these metals are attributed to the involvement of greater number of electrons from (n – 1)d in addition to ns electrons in the interatomic metallic bonding.
Which transition metal is liquid at room temperature ?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Hg
Mercury is the only metal that is a liquid at room temperature (melting point 234 K). Its d subshell is completely filled (Hg, Z = 80: [Xe]4f145d106s2), so no d electrons take part in metallic bonding, and its 6s electrons are held very tightly. The metallic bonding is therefore very weak.