Question

It has been found by mass spectrometric analysis that in nature, the relative abundances of the various isotopic atoms of silicon are 92.23%
Si 28 , 4.67% Si 29 and 3.1% Si 30 . Calculate the atomic weight of silicon, in correct significant figures, from this information and from the
nuclidic masses. Nuclidic masses: Si 28 27.97693 amu, Si 29 28.97649 amu, Si 30 29.97377 amu. plssssss help me

Answer 1

Answer:

This means that the isotope of silicon with a mass number of 28 is by far the most common of these three isotopes.

Explanation:

The abundance of Si-28 is 92.23%. Si-29 is 4.68% and Si-30 is 3.09%.

Because most Si atoms have a mass of 28 amu, the average mass of all silicon atoms is very close to 28.

Here is a video which summarizes how to calculate average atomic mass from data about mass and relative abundance.