Standard (pre-2019):

Alternative 1:

Alternative 2:

Alternative 3:

The Coulomb constant

$k_e=\frac{1}{4\pi {\epsilon }_0}=c^2\times {10}^{-7}$

$k_e=c^2$

$k_e=c$

Elementary charge

$e=\sqrt{\frac{\hslash }{c}\alpha \times {10}^7}$

$e=\sqrt{\frac{\hslash }{c}\alpha }$

$e=\sqrt{\hslash \alpha }$

$e=\sqrt{\hslash \alpha c}$

Planck charge

$q_p=\sqrt{\frac{\hslash }{c}\times {10}^7}$

$q_p=\sqrt{\frac{\hslash }{c}}$

$q_p=\sqrt{\hslash }$

$q_p=\sqrt{\hslash c}$

The Coulomb force

$F=k_e\frac{qq}{r^2}$

$F=c^2\frac{qq}{r^2}$

$F=c\frac{qq}{r^2}$

$F=\frac{qq}{r^2}$

The Coulomb force elementary charges

$F=k_e\frac{ee}{r^2}=\hslash \frac{c\alpha }{r^2}$

$F=c^2\frac{ee}{r^2}=\hslash \frac{c\alpha }{r^2}$

$F=c\frac{ee}{r^2}=\hslash \frac{c\alpha }{r^2}$

$F=\frac{ee}{r^2}=\hslash \frac{c\alpha }{r^2}$

Coulomb force Planck charges

$F=k_e\frac{q_p{q}_p}{r^2}=\hslash \frac{c}{r^2}$

$F=c^2\frac{q_p{q}_p}{r^2}=\hslash \frac{c}{r^2}$

$F=c\frac{q_p{q}_p}{r^2}=\hslash \frac{c}{r^2}$

$F=\frac{q_p{q}_p}{r^2}=\hslash \frac{c}{r^2}$