What is the Coulomb force between an electron on the outskirts of the atom and a proton in the nucleus if they are 1.40 x 10^-10m apart?

You are going to calculate the various forces at play in a particular atom. Remember from Chemistry that an atom consists of electrons orbiting a nucleus made up of protons and neutrons.

1 Answer
Jul 29, 2018

From Coulomb’s Law force between two charges #q_1and q_2# located at a distance #r# from each other is

#vecF_e = k (q_1*q_2)/r^2hatr#
where k is Coloumb’s constant #=8.99xx10^9\ Nm^2C^-2#

We know that an electron carries the elementary charge #q = -e# and the proton carries the same charge but is positive #q = +e#
#e= 1.602xx10^-19\ C#. Inserting given values in the expression we get

#vecF_e = 8.99xx10^9xx (1.602xx10^-19*(-1.602xx10^-19))/(1.40 xx 10^-10)^2hatr#
#=>vecF_e = -1.06xx10^-5hatr\ N#

negative sign shows that the force is attractive.