# Question bde5e

Apr 15, 2015

The average atomic mass 238.03 can be calculated by the following equation where $x$ is the percentage abundance of U-235 and $y$ is the percent abundance of U-238

$238.03 = \frac{\left(x\right) \left(235.044\right) + \left(y\right) \left(238.051\right)}{100}$
and $x + y = 100$

substitution gives

$23803 = 235.044 x + 238.051 \left(100 - x\right)$
$23803 = 235.044 x + 23805.1 - 238.051 x$
$- 3.007 x = - 2.099$
x=0.7%#