What happens to the electric force between two particles if the distance between them is doubled?

The size of the force varies inversely as the square of the distance between the two charges. Therefore, if the distance between the two charges is doubled, the attraction or repulsion become weaker, decreasing to one-fourth of the original value. ...The size of the force is proportional to the value of each charge.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

since electrons are negative the answer is neagtaive