Chapter 42 - Nuclear Physics - Exercises and Problems - Page 1237: 40

The percent abundance of $^{69}Ga$ is $~~\%60$

Let $x$ be the relative abundance of $^{69}Ga$ Then the relative abundance of $^{71}Ga$ is $~~1-x$ We can find $x$: $(68.92~u)(x) + (70.92~u)(1-x) = 69.72~u$ $68.92~x + 70.92- 70.92~x = 69.72$ $2x = 70.92-69.72$ $2x = 1.20$ $x = 0.60$ The percent abundance of $^{69}Ga$ is $~~\%60$