What is the electrons electrostatic potential energy at this

What is the electron\'s electrostatic potential energy at this orbit distance (0.0529nm) away from the proton?

Solution

charge of electron

q=-1.602*10^-19 C

charge of proton

q=1.602*10^-19C

Electrostaic potential energy

U=KQ₁Q₂/r

where K=1/4pie₀=9*10⁹

U=(9*10⁹)(1.602*10^-19)(-1.602*10^-19)/(0.0529*10^-9)

U=-4.366*10^-18 J