Question

Which of the following statement is INCORRECT?

• A. Transition metals and many of their compounds show paramagnetic behaviour.
• B. The enthalpies of atomisation of the transition metals are high.
• C. The transition metals generally form coloured compounds.
• D. Transition metals and their many compounds act as good catalyst.
• E. Zn, Cd and Hg are very hard and have very low volatility.

Hint:

Elements with completely filled \(d^{10}\) configuration like Zn, Cd, Hg behave differently from typical transition metals and are softer with lower melting points.

Answer 1

Answer: (E)

Step 1: Analyze statement (1).
Transition metals have unpaired \(d\)-electrons, so they show paramagnetism. This statement is correct.

Step 2: Analyze statement (2).
They have strong metallic bonding due to participation of \(d\)-electrons, leading to high enthalpy of atomisation. This is correct.

Step 3: Analyze statement (3).
Transition metals form coloured compounds due to \(d-d\) electronic transitions. This is also correct.

Step 4: Analyze statement (4).
Transition metals and their compounds act as catalysts due to variable oxidation states and surface adsorption. This is correct.

Step 5: Analyze statement (5).
Zn, Cd and Hg have completely filled \(d^{10}\) configuration. They are relatively soft metals and mercury is liquid at room temperature, showing high volatility. Thus, this statement is incorrect.

Step 6: Identify the incorrect statement.
Only statement (5) contradicts known properties of these elements.

Step 7: Final answer.
\[ \boxed{\text{Zn, Cd and Hg are very hard and have very low volatility}} \] which matches option \((5)\).