chlorine has two isotopes chlorine-35 has an actual mass of 34.9689 amu and chlorine-37 has a mass of 36.9659 in any sample of chlorine atoms 75.711% will be chlorine-35 and 24.229% will be chlorine-37 calculate the average atomic mass of chlorine

35.48948 u

Explanation:

Technically u need to multiply the amu with the percentage of the specific isotope. Because it's a percentage u need to divide by 100. When. You get ur final answers u add the two to get the average atomic mass for the Chlorine.

I hope I helped I suck at explaining

35 x 75.711% / 100 = 26.49885 u

37 x 24.229% / 100 = 8.99063 u

26.49885 + 8.99063 = 35.48948u if u need to round off the nr it will be 35.49 u