Question

How do you calculate the relative atomic mass of an element given the abundances with no calculator?

Answer 1

General formula of relative abundance is M1(x) + M2(1-x) = Me

Me is relative atomic mass of the element from the periodic table,

M1 is mass of isotope for which you know the abundance,

x is the relative abundance of the know isotope,

M2 is mass of the isotope of unknow abundance.

Here, we need to calculate Relative atomic mass from abundances

we taken example of Carbon, The abundance of nitrogen C12 isotope is 99% and abundance of C13 isotope is 100 - 99 = 1%

Me = 12 * 99% + 13 * 1% =(12 * 99/100 ) + (13 *1/100 )= 12.01