The nucleus of a plutonium-239 atom contains 94 protons. Assume that the nucleus is a sphere with radius 6.64 fm and with the charge of the protons uniformly spread through the sphere. At the surface of the nucleus, what are the (a) magnitude and (b) direction (radially inward or outward) of the electric field produced by the protons

(a) E = 3.065 * 10^21 N/C

(b) The direction is radially outward.

Explanation:

Parameters given:

Number of protons = 94

Charge of proton = 1.6023 * 10^-19 C

Radius of nucleus = 6.65 fm = 6.65 * 10^-15

At the surface of the nucleus, Electric field, E is given as:

E = kq/r^2

Where k = Coulombs constant

r = radius of nucleus

=> E = (9 * 10^9 * 94 * 1.6023 * 10^-19) / (6.65 * 10^21)

E = 3.065 * 10^21 N/C

The direction of the field is radially outward.