Ions, electrons, and ionizing radiations / by James Arnold Crowther.
- James Arnold Crowther
- Date:
- 1919
Licence: Public Domain Mark
Credit: Ions, electrons, and ionizing radiations / by James Arnold Crowther. Source: Wellcome Collection.
279/300 page 259
![should theoretically be able to emit eight electrons. Its system: is an exceedingly stable one, and the force required to remove an electron would thus be very large, probably too large to be exerted by the action of another atom upon it, so that it is unlikely that this valency would be increased. Again it will not be able to absorb an electron into its system, and thus acquire a negative valency, for if it did so it would have to form an outer ring of 18. As this system even when neutral is very unstable it would obviously be even more so if negatively charged. The atom h is therefore incapable of shewing either a positive or a negative valency. It thus corresponds to one of the inert gases, such as argon for example. On the other hand, the preceding element in the series fh will obviously tend to acquire an extra electron since this would increase its stability. It could not, however, acquire more than one, for as the preceding argument shows, this would lead to complete insta- bility. It would, therefore, behave as a monovalent electro- negative element, corresponding thus to chlorine. Similarly g would have a negative valency of two and so on. The results for this series of elements are summarized in the following table. a b G d € ci g h Total number of electrons 42 43 4h 45 46 47 48 49 Positive valency 1 2 3 4 5 6 a (8) Negative valency a 6 5 4 3 2 ] Element Na Mg Al Si LP Cl A Atomic number 1] 12 13 14 15 16 17 18 Positive valency 1 2 3 4 5 6 7 0 Negative valency 7 6 5 + 3 2 1 0 The corresponding properties of the elements from sodium to argon are placed below for comparison. The numbers are illustrative only. As we have seen, the actual number of electrons in the various rings has yet to be determined. It suffices, however, to illustrate the fact that some such arrangement as the periodic table is a natural result of the electron theory of the structure of the atom. 17—2](https://iiif.wellcomecollection.org/image/b32782032_0279.jp2/full/800%2C/0/default.jpg)
