Answer:
40.5% is abundance of X-122
Explanation:
we know there are two naturally occurring isotopes of X, X-120 and X-122.
First of all we will set the fraction for both isotopes
X for the isotopes having mass 122
1-x for isotopes having mass 12
0
The average atomic mass of X is 120.81 amu
we will use the following equation,
122x + 120 (1-x) = 120.81
122x + 120 - 120x = 120.81
122x- 120x = 120.81 -120
2x = 0.81
x= 0.81/2
x= 0.405
0.405 × 100 = 40.5%
40.5% is abundance of X-122 because we solve the fraction x.
now we will calculate the abundance of X-120.
(1-x)
1 - 0.405 = 0.595
0.595 × 100 = 59.5 %
59.5 % for X-120.
