Chlorine consisting of two isotope of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotope of mass number 37

A.

20

B.

25

C.

60

D.

75

Correct answer is B

Let the relative abundance of the energy with mass 37 be
Total relative abundance of the isotope of mass 359100-k)
Total mass of isotope of mass 37-37x, while that of 35-359(100x)
-37x + 3500 − 35 − 35.5
-37x + 3500 − 35n − 35.5
Mean mass of chlorine atom − (2n + 3500)/ ÷ 100
= 35.5
2x + 3500 − 3550yx = 50/2