4) What is the electrical charge (+, 0 or -) of each subatomic particle and how do their charges affect the net charge (or overall charge) of the atom?

Explanation:

Problem:

 What is the electrical charge of each subatomic particle and how do the charges affects the net charge?

 In atom, there are 3 subatomic particles:

Protons are positive charged particles with a charge of +

Electrons are negatively charged with a charge of -

Neutrons do not carry any charges 0

 The net charge;

  Net charge  = number of protons - number of electrons

When the number of protons is more than number of electrons, there is a positive net charge on the ion.

When the number of electrons is more, there is a negative net charge on the ion.

a is the correct answer