Question

question 21 (1 point)
which of the following atoms is paramagnetic in the ground state?
ca
c
ne
zn
question 22 (1 point)
which of the following metal ions will repel an external magnetic field?
fe²+
mn²+
zn²+
ni²+
cu²+

Explanation:

Question 21

• Ca (Calcium): Its electron configuration is \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}\). All electrons are paired.
• C (Carbon): Electron configuration \(1s^{2}2s^{2}2p^{2}\). In the \(2p\) sub - shell, there are two unpaired electrons (Hund's rule: electrons occupy degenerate orbitals singly as far as possible).
• Ne (Neon): Electron configuration \(1s^{2}2s^{2}2p^{6}\). All electrons are paired.
• Zn (Zinc): Electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}\). All electrons are paired.

Paramagnetic substances have unpaired electrons.

• A substance that repels an external magnetic field is diamagnetic. Diamagnetic substances have no unpaired electrons.
• \(Fe^{2 +}\): Electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{6}\). There are 4 unpaired electrons in the \(3d\) sub - shell.
• \(Mn^{2+}\): Electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{5}\). There are 5 unpaired electrons in the \(3d\) sub - shell.
• \(Zn^{2+}\): Electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}\). All electrons are paired.
• \(Ni^{2+}\): Electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{8}\). There are 2 unpaired electrons in the \(3d\) sub - shell.
• \(Cu^{2+}\): Electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{9}\). There is 1 unpaired electron in the \(3d\) sub - shell.

Answer:

C

Question 22