A proton and an electron are placed 1.6 cm apart in free space. Find the magnitude of electrostatic force between them. The nature of this force.

Given data: a proton and an electron are placed 1.6cm apart in free space.

Concept used: coulomb’s law

Detailed solution:

Charge of proton= $1.6\times {10}^{-19}C$

Charge of electron=$1.6\times {10}^{-19}C$

Distance r= $1.6\times {10}^{-2}m$

Force ,  

 $F=\frac{k{q}_1{q}_2}{r^2}$

 $F=9\times {10}^{-25} \mathrm{N}$

Hence, option(C) is the solution.