Colourless ion among the following is:

1.	Cr+4	2.	Sc+3
3.	Ti+3	4.	V+3

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:
 

Ion that gives color with water is:

1. $C{u}^{+}$

2. $C{r}^{3+}$

3. $N{a}^{+}$

4. None of the above.

Maximum oxidation state is shown by:
1.  La
2.  Gd
3.  Eu
4.  Am

Which of the following is a coloured and paramagnetic compound?

1. CuF₂

2. K₂Cr₂O₇

3. $KMn{O}_4$

4. K₄[Fe(CN)₆]

Lanthanoids are:
 

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

1. Zn

2. K

3. Ca

4. Fe

\(FeCr_{2}O_{4} \) when reacts with $N{a}_{2}C{O}_3$ gives the product: 

1. $N{a}_{2}Cr{O}_4$

2. $N{a}_{2}C{r}_2{O}_7$

3. $F{e}_3{O}_4$

4. FeO

A set of ions among the following that have a 3d² electronic configuration is:

1. ${\mathrm{Ti}}^{+},{\mathrm{V}}^{4+},{\mathrm{Cr}}^{6+},{\mathrm{Mn}}^{7+}$

2. ${\mathrm{Ti}}^{4+},{\mathrm{V}}^{3+},{\mathrm{Cr}}^{2+},{\mathrm{Mn}}^{3+}$

3. ${\mathrm{Ti}}^{2+},{\mathrm{V}}^{3+},{\mathrm{Cr}}^{4+},{\mathrm{Mn}}^{5+}$

4. ${\mathrm{Ti}}^{3+},{\mathrm{V}}^{2+},{\mathrm{Cr}}^{3+},{\mathrm{Mn}}^{4+}$