An element X has two isotopes, \(^{20} _{10}X\) and \(^{22} _{10}X\),
present in the ratio 1:3. The relative atomic mass of X would be?
- 20.5
- 21.0
-
21.5
- 22.0
- 22.5
The correct answer is: C
Explanation
The relative atomic mass will be [(20 * 1) + (3 * 22)] / (4)
(86)/(4) = (43)/(2) = 21.5