Answer:
40.7% abundance of Ga-71
59.93% abundance of Ga-69
Explanation:
Given data:
Average atomic mass of Ga = 69.72 amu
Atomic mass of Ga-69 = 68.9257 amu
Atomic mass of Ga-71 = 70.908 amu
Percent abundance of each isotope = ?
Solution;
we know there are two naturally occurring isotopes of Ga.
First of all we will set the fraction for both isotopes
X for the isotopes having mass 68.9257
1-x for isotopes having mass 70.908
we will use the following equation,
68.9257x + 70.908
(1-x) = 69.72
68.9257x +70.908 - 70.908x = 69.72
68.9257x - 70.908x = 69.72 - 70.908
-1.9823x = - 1.188
x= 1.188/1.9823
x= 0.5993
0.5993 × 100 = 59.93 %
59.93 % is abundance of Ga-69 because we solve the fraction x.
now we will calculate the abundance of Ga-71.
(1-x)
1 - 0.5993 = 0.4007
0.4007× 100= 40.7 %
40.7 % for Ga-71.
