- #1

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## Homework Statement

Knowing the Z (number of protons) of an element, how can I find N (number of neutrons) or A (mass number) of the element?

## Homework Equations

I tried to use the semi-empirical mass formula E

_{B}= α

_{ν}Α - α

_{s}A

^{2/3}- α

_{c}Z

^{2}/A

^{1/3}- α

_{Α}(Α-2Ζ)

^{2}/Α - δ(Α,Ζ) for this.

## The Attempt at a Solution

I[/B] tried to to find the maximum binding energy by dE

_{b}/dA=0 for a given Z number. I came to the following equation where I substituted Z=32 as an example for Germanium:

2113.9 A

^{2}- 11.4 A

^{4/3}+ 352.16 A

^{2/3}+ 67665.92 = 0

Now I can't find a way to solving for A. Only way to find A that I can see is by substituting numerically values for A and see when the equation is valid.