10: Some Properties of Actinium and Actinoids
Electronic conifigurations*
Radii/pm
Atomic
Name
Symbol
M
M
3+
M
4+
M
3+
M
4+
Number
89
Actinium
Ac
 6d
17s
2
5f 
0
111
90
Thorium
Th
 6d
27s
2
5f 
1
5f 
0
99
91
Protactinium
Pa
 5f 
26d
17s
2
5f 
2
5f 
1
96
92
Uranium
U
 5f 
36d
17s
2
5f 
3
5f 
2
103
93
93
Neptunium
Np
 5f 
46d
17s
2
5f 
4
5f 
3
101
92
94
Plutonium
Pu
 5f 
67s
2
5f 
5
5f 
4
100
90
95
Americium
Am
 5f 
77s
2
5f 
6
5f 
5
99
89
96
Curium
Cm
 5f 
76d
17s
2
5f 
7
5f 
6
99
88
97
Berkelium
Bk
 5f 
97s
2
5f 
8
5f 
7
98
87
98
Californium
Cf
 5f 
107s
2
5f 
9
5f 
8
98
86
99
Einstenium
Es
 5f 
117s
2
5f 
10
5f 
9
–
–
100
Fermium
Fm
 5f 
127s
2
5f 
11
5f 
10
–
–
101
Mendelevium
Md
 5f 
137s
2
5f 
12
5f 
11
–
–
102
Nobelium
No
 5f 
147s
2
5f 
13
5f 
12
–
–
103
Lawrencium
Lr
 5f 
146d
17s
2
5f 
14
5f 
13
–
–
Fig 4 7: Chemical reactions of the lanthanoids Rationalised 2023-24
112
Chemistry
The actinoids are radioactive elements and the earlier members have
relatively long half-lives, the latter ones have half-life values ranging from
a day to 3 minutes for lawrencium (Z =103) The latter members could be
prepared only in nanogram quantities