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Give reasons for the following.
The melting points and boiling points of , and are low. (Atomic number of , and )
The melting points and boiling points of $\text{Zn}$, $\text{Cd}$ and $\text{Hg}$ are low. (Atomic number of $\text{Zn} = 30$, $\text{Cd} = 48$ and $\text{Hg} = 80$)
Answer
Answer
Official answer keyIn Zn, Cd and Hg all the electrons in the d-subshell are paired ($d^{10}$), so there is no contribution from d electrons to metallic bonding. The metallic bonds are therefore weak, and the melting and boiling points are low.
From ISC 2027 Specimen Chemistry Paper 1, question 7(ii).