Four successive members of the first-row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionization enthalpy:

1. Vanadium (Z = 23)

2. Manganese (Z = 25)

3. Chromium (Z = 24)

4. Iron (Z = 26)

Colourless ion among the following is:

An element among the following that exhibits the maximum oxidation state is:

1. Cr

2. Mn

3. Fe

4. V

The main reason for a larger number of oxidation states exhibited by the actinoids than the corresponding lanthanoids is:

Find the ion that shows colour in aqueous solution:

1. $C{u}^{+}$

2. $C{r}^{3+}$

3. $N{a}^{+}$

4. None of the above.

Maximum oxidation state is shown by:

Which of the following is a coloured and paramagnetic compound?

1. CuF₂

2. K₂Cr₂O₇

3. $KMn{O}_4$

4. K₄[Fe(CN)₆]

Which of the following statements correctly describes lanthanoids?

Which of the following elements can combine with chlorine to form more than one binary compound?

1. Zn

2. K

3. Ca

4. Fe

Chromite ore (FeCr₂O₄) is fused with sodium carbonate (Na₂CO₃) in the presence of air (oxygen). The reaction is part of the industrial extraction of chromium.

The major chromium-containing product X formed in the reaction FeCr₂O₄ + Na₂CO₃ → X
(along with other products like Fe₂O₃ and CO₂) is: