The electron, its isolation and measurement and the determination of some of its properties
John Stuart Mill · en
30 Zn
2
4
4
6
6
6
2
31 Ga
2
4
4
6
6
6
2
1
36 Kr
2
4
4
6
6
6
4
4
5
37 Rb
2
4
4
6
6
6
4
4
1
38 Sr
2
4
4
6
6
6
4
4
2
39 Y
2
4
4
6
6
6
4
4
1
(2)
40 Zr
2
4
4
6
6
6
4
4
2
(2)
47 Ag
2
4
4
6
6
6
6
6
6
1
48 Cd
2
4
4
6
6
6
6
6
6
2
49 In
2
4
4
6
6
6
6
6
6
2
1
54 Xe
2
4
4
6
6
6
6
6
6
4
4
6
55 Cs
2
4
4
6
6
6
6
6
6
4
4
1
56 Ba
2
4
4
6
6
6
6
6
6
4
4
2
57 La
2
4
4
6
6
6
6
6
6
4
4
1
(2)
58 Ce
2
4
4
6
6
6
6
6
6
1
4
4
1
(2)
59 Pr
2
4
4
6
6
6
6
6
6
2
4
4
1
(2)
71 Lu
2
4
4
6
6
6
8
8
8
8
4
4
1
(2)
72 Hf
2
4
4
6
6
6
8
8
8
8
4
4
2
(2)
79 Au
2
4
4
6
6
6
8
8
8
8
6
6
6
1
80 Hg
2
4
4
6
6
6
8
8
8
8
6
6
6
2
81 Ti
2
4
4
6
6
6
8
8
8
8
6
6
6
2
1
86 Nt
2
4
4
6
6
6
8
8
8
8
6
6
6
4
4
7
87 ——
2
4
4
6
6
6
8
8
8
8
6
6
6
4
4
1
88 Ra
2
4
4
6
6
6
8
8
8
8
6
6
6
4
4
(2)
89 Ac
2
4
4
6
6
6
8
8
8
8
6
6
6
4
4
1
(2)
90 Th
2
4
4
6
6
6
8
8
8
8
6
6
6
4
4
2
(2)
118 (?)
2
4
4
6
6
6
8
8
8
8
8
8
8
8
6
6
6
4
4
[Pg 228]
The seventh period begins (Fig. 30) with an unknown
element of atomic number 87, which, with its single
orbit, should have a valency of 1, then passes to radium
with its two orbits (see Fig. 31) and valency 2, and
breaks off suddenly with uranium because the nucleus
has here become unstable.
It should be clearly understood that the detailed theory as here
presented, and above all the models of complicated atoms, are to a very
considerable degree hypothetical and speculative. But it is highly
probable that they give a more or less correct general picture
of the way electrons behave in atoms. So far as the general conception
of orbits which behave in the main, especially in the simpler atoms,
in accordance with the Bohr assumptions, is concerned, if the test of
truth in a physical theory is large success both in the prediction
of new relationships and in correctly and exactly accounting for old
ones, the theory of non-radiating orbits is one of the well-established
truths of modern physics. For the present at least it is truth, and no
other theory of atomic structure need be considered until it has shown
itself able to approach it in fertility. I know of no competitor which
is as yet even in sight.