An introduction to the study of chemistry / by Ira Remsen.

  • Ira Remsen
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of chemistry / by Ira Remsen. Source: Wellcome Collection.

    398/410 (page 382)
    VI. form strong acids, as do those of Group VII. If we know the atomic weight of an element we can say ap- proximately where it belongs in the table, and can from its position determine its properties with considerable ac- curacy. When the table was first constructed, the two elements scandium and gallium were undiscovered. It was seen, however, that the gaps existed, and it was pre- dicted that elements would be found with atomic weights approximately 44 and 69 respectively, and that these ele- ments would have certain properties which were clearly described. It was suggested that the element with the atomic weight 44 would bear to calcium and titanium about the same relation that aluminium bears to magne- sium and silicon. The predictions were soon after con- firmed, and the description of the element given before it was discovered was found to be singularly correct. Un- questionably the properties of the elements are determined by their atomic weights. An element whose atom weighs 100 times as much as that of hydrogen must have certain definite properties. It must combine with hydrogen and with oxygen in certain proportions; it must be allied to the members of the chlorine family; its properties are the result of that particular weight. Further, it seems to fol- low that the elements are not entirely independent forms of matter, but that they are in all probability compounds of a small number of simple elements at present unknown to us. Of this, however, we have no evidence, and until some one succeeds in isolating one or more of these subtler elements it is almost useless to speculate in regard to them.