Question

3. An element has an amu of 1.045 with a relative abundance of 89% an isotope of this element has an amu of 2.014 and has a relative abundance of 4.7%. what is atomic weight of that element?

Answer 1

To find atomic weight of the element, we need to add weights of its isotopes multiplied by relative abundance:

$A_{r, std} = 1.045 \cdot 0.89 +2.014 \cdot0.047 = 1.0245$ a.m.u.

Answer: $A_{r,std}= 1.0245$ a.m.u.