Saved Bookmarks
| 1. |
#MY QUESTION# |
|
Answer» Doberenier arranged elements in the form of triad ( 3 elements in a group) in such a way that the middle ELEMENT of the triad had both atomic mass and PROPERTIES roughly equal to the average of the other two elements of the triad. for EXAMPLE lithium (7) ,Na(23),k(39): =7+39/2 =23 |
|