The most common oxidation state for lanthanoids and actinoids is:

Which one of the following is a diamagnetic ion?

Actinoids show a greater number of oxidation states than lanthanoids because:  

The electronic configuration of the last element of actinoids is :

1. Thorium, Th: $\left[\mathrm{Rn}\right]5{\mathrm{f}}^{14}6{\mathrm{d}}^{1}7{\mathrm{s}}^2$

2. Lawrencium, Lr: $\left[\mathrm{Rn}\right]5{\mathrm{f}}^{14}6{\mathrm{d}}^{1}7{\mathrm{s}}^2$

3. Neptunium, Np: $\left[\mathrm{Rn}\right]5{\mathrm{f}}^{14}6{\mathrm{d}}^{1}7{\mathrm{s}}^2$

4. Protactinium, Pa: $\left[\mathrm{Rn}\right]5{\mathrm{f}}^{14}6{\mathrm{d}}^{1}7{\mathrm{s}}^2$

From the following, which is the most basic hydroxide?

1. Ce(OH)₃

2. Lu(OH)₃

3. Yb(OH)₃

4. Tb(OH)₃

Give below are some atomic numbers:

29, 59, 74, 95, 102, 104
The atomic numbers of the inner transition elements among the above are :