The mass number of three isotopes of an element are `11,12 and 13` .Their percentage ohandances `80,15 and 5`, respectively .What is the atomic weight of the element ?

Options

A. `11.25`
B. `20`
C. `16`
D. `10`

Explanation

To find the atomic weight of the element with three isotopes having mass numbers of 11, 12, and 13 and their respective percentage abundances of 80%, 15%, and 5%, we can follow these steps:

### Step 1: Convert percentage abundances to decimal form
To use the percentage abundances in calculations, we convert them into decimal form by dividing by 100.

- For isotope with mass number 11:
\[
\text{Abundance} = \frac{80}{100} = 0.80
...