Question

What is the average atomic mass of silicon based on the given isotopic abundances?

a) 27.96 u
b) 28.09 u
c) 28.42 u
d) 29.15 u

Answer 1

The average atomic mass of silicon is 28.09 u based on the given isotopic abundances.

Step-by-step explanation:

The average atomic mass of silicon can be calculated based on the given isotopic abundances. Silicon has three isotopes: Silicon-28, Silicon-29, and Silicon-30. The abundances of these isotopes are 92.22%, 4.67%, and 3.10% respectively. The atomic masses of these isotopes are 27.9769 u, 28.9865 u, and 29.9825 u respectively.

To calculate the average atomic mass, we multiply the abundance of each isotope by its atomic mass, then sum them up. This calculates to: (92.22% * 27.9769 u) + (4.67% * 28.9865 u) + (3.10% * 29.9825 u) = 28.086 u. Therefore, option B) 28.09 u is the average atomic mass of silicon based on the given isotopic abundances.