4 General
Characteristics
and Comparison
with Lanthanoids
Ac
Th
Pa
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
3
3
3
3
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
5
5
5
5
5
6
6
6
6
7
7
Table 4 11: Oxidation States of Actinium and Actinoids
Rationalised 2023-24
113
The d- and f- Block Elements
The actinoids are highly reactive metals, especially when finely divided The action of boiling water on them, for example, gives a mixture of oxide
and hydride and combination with most non metals takes place at
moderate temperatures Hydrochloric acid attacks all metals but most are
slightly affected by nitric acid owing to the formation of protective oxide
layers; alkalies have no action