NEET Chemistry: Chemistry - d and f Block Elements questions with solutions

Q1. Most of the transition metals exhibit: (i) paramagnetic behaviour (ii) diamagnetic behaviour (iii) variable oxidation states (iv) formation of coloured ions

1. (ii), (iii) and (iv)
2. (i), (iii) and (iv)
3. (i), (ii) and (iii)
4. (i), (ii) and (iv)

Answer: (i), (iii) and (iv)

Most transition metals have partially filled d-orbitals, so they usually show paramagnetism due to unpaired electrons. Their variable oxidation states and coloured ions also arise from the d-electron configuration and d–d transitions. Diamagnetism is not a general property of most transition metals.

Q2. Transition metals are less reactive than alkali metals because they have:

1. high ionisation potential and low melting point
2. high ionisation potential and high melting point
3. low ionisation potential and low melting point
4. low ionisation potential and high melting point

Answer: high ionisation potential and high melting point

Transition metals are less reactive because their electrons are not removed as easily, so they have higher ionisation potential. They also generally have stronger metallic bonding, giving them higher melting points.