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Give reasons for the following.
Cobalt is attracted in a magnetic field whereas Zinc is not. (Atomic number of and )
Cobalt is attracted in a magnetic field whereas Zinc is not. (Atomic number of $\text{Co} = 27$ and $\text{Zn} = 30$)
Answer
Answer
Official answer keyCobalt ($\mathrm{[Ar]3d^74s^2}$) has $3d^7$ electrons in its outer shell, giving three unpaired electrons, so it is paramagnetic and is attracted in a magnetic field. Zinc ($\mathrm{3d^{10}4s^2}$) has a completely filled $d^{10}$ configuration with no unpaired electrons, so it is diamagnetic and is not attracted.
From ISC 2027 Specimen Chemistry Paper 1, question 7(i).