Write one similarity and one difference between the chemistry of lanthanoids and that of actinoids.

Lanthanoids are the fourteen elements following Lanthanum and Actinoids are the fourteen elements following Actinium in the periodic table.

The similarity between their chemistry is as follows:

(i) Both groups involve the filling of f-orbital (i.e. 4f and 5f)

(ii) Both groups show contraction i.e. Lanthanoids contraction and actinoide contraction, i.e., gradual decrease in the atomic and ionic size across the series.

The differences between the two groups are as follows: