Substantiate the following statements with reasons. Cobalt is attracted in a magnetic field whereas…
Substantiate the following statements with reasons.
(i)
Cobalt is attracted in a magnetic field whereas Zinc is not. (Atomic number of $\text{Co} = 27$ and $\text{Zn} = 30$)
(ii)
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 (i)
AIWritten by AI (gemini) - it can contain mistakes.
Cobalt ($Z=27$) has electronic configuration $[\text{Ar}]3d^7 4s^2$, having 3 unpaired electrons, hence it is paramagnetic and attracted in a magnetic field. Zinc ($Z=30$) has electronic configuration $[\text{Ar}]3d^{10} 4s^2$, having no unpaired electrons, hence diamagnetic and not attracted.
Answer (ii)
AIWritten by AI (gemini) - it can contain mistakes.
In $\text{Zn}$, $\text{Cd}$ and $\text{Hg}$, the $d$-subshell is completely filled ($d^{10}$) and no unpaired electrons are available for metallic bonding. The metallic bonds are weak, resulting in low melting and boiling points.
From ISC 2027 Specimen Chemistry Paper 1, question 7.