The following graph shows the relative abundances of the naturally occurring silicon isotopes.

Question

Silicon is the second most abundant element in Earth’s crust. It is used in the electronics industry to manufacture transistors, and in the construction industry to produce concrete and Portland cement. 

The following graph shows the relative abundances of the naturally occurring silicon isotopes.

 

What could be the estimated (rounded to one decimal place) atomic mass of Silicon?

1. 30.1 amu
2. 30.1 amu
3. 26.2 amu
4. 26.2 amu
5. 28.1 amu
6. 28.1 amu
7. 29.8 amu

Answer 1

28.1 because >92% is Si-28