Question

answer this question

Answer 1

151.02041 amu is the mass of natural chlorine

Answer 2

use a weighted average to find the average mass
to find non-weighted, normal averages, we just add the values and divide by number of values, but for weighted average, we multiply each value by the  rate at which it is present
-so for this problem
average atomic mass=35*(75.5/100)+37*(24.5/100)=35*0.755+37*0.245
=26.425+9.065= 35.49
-hope this helps