Which is a sub-atomic particle?

a). compound

b). electron

c). isotope

d). neuron

Ithink it is letter b, i may be wrong but i think that is the answer

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.