Answer:
The answer is "[tex]1.01 \times 10^{-13}[/tex]"
Explanation:
Using the law of conservation for energy. Equating the kinetic energy to the potential energy.
[tex]KE=U=\frac{kqq'}{r}\\\\[/tex]
Calculating the closest distance:
[tex]\to r=\frac{kqq'}{KE}\\\\[/tex]
[tex]=\frac{k(2e)(79e)}{KE}\\\\=\frac{k(2)(79)e^2}{KE}\\\\=\frac{9.0\times 10^9 \ N \cdot \frac{m^2}{c}(2)(79)(1.6 \times10^{-19} \ C)^2}{(2.25\ meV) (\frac{1.6 \times 10^{-13} \ J}{1 \ MeV})}\\\\[/tex]
[tex]=\frac{9.0\times 10^9 \times 2\times 79\times 1.6 \times10^{-19}\times 1.6 \times10^{-19} }{(2.25 \times 1.6 \times 10^{-13}) }\\\\=\frac{3,640.32\times 10^{-29}}{3.6 \times 10^{-13} }\\\\=\frac{3,640.32}{3.6} \times 10^{-16}\\\\=1011.2 \times 10^{-16}\\\\=1.01 \times 10^{-13}[/tex]
