Question

Describe how you would determine the isotopic abundance of an element from its mass spectrum.

Answer 1

let,s take example for understand this

boron as atomic no 5 .

The two peaks in the mass spectrum shows that there are 2 isotopes of boron - with relative isotopic masses of 10 and 11 on the 12C scale.

there are two peaks the tallest peak is often given an arbitrary height of 100 (consaider the maximum height of peak as 100) . In this case, the two isotopes (with their relative abundances) are

boron - 10 23

boron - 11 100

if u want to calculate the relative atomic mass u can easily find out using above values

the total mass = (23 * 10 ) + (100*11) = 1330

the average mass of these 100 +23 atom=123 atom = 1330/123 = 10.8130