Copper:
r
x = 9 X 5 = 45
Zircon:
r
x = 4.7 X 9 = 42.3
Since
m
_{m}
is the same in each case then if
r
x = 45 just absorbs all the
b
s then
r
x = 42.3 will be insufficient.
Return to Self Test 2