Charges and Electric Field

Protons carry a positive charge, electrons carry a negative charge, and neutrons carry no charge at all.

The atom has 6 protons (charge = $+6$) and 6 electrons (charge = $-6$). The neutrons contribute nothing.

Total charge $=+6+(-6)=0$. The charges cancel exactly.

Because the number of protons equals the number of electrons, the atom is electrically neutral. This is the normal state for any atom.

We need to find the overall electric charge of an atom with equal numbers of protons and electrons.

Neutrons have no charge, so comparing protons to neutrons is irrelevant. Only protons and electrons determine the charge.

The location of electrons (outside the nucleus) does not make the atom negative. What matters is whether the number of electrons exceeds the number of protons — here they are equal.

Neutrons are neutral and do not contribute to charge. Adding them to protons to compare against electrons is incorrect reasoning.

'Neutral, because the positive and negative charges cancel out' is correct — 6 positive charges from protons and 6 negative charges from electrons sum to zero.

An object becomes negatively charged when it gains electrons — because electrons carry negative charge.

Only electrons can be transferred between objects during friction. Protons are locked in the nucleus and do not move in everyday situations.

Since the balloon became negatively charged, it must have gained electrons. Those electrons must have come from the hair.

Electrons transferred from the hair to the balloon. This also explains why the hair becomes positively charged — it lost electrons.

The balloon is negatively charged after rubbing, meaning it gained negative charge. We need to identify the correct particle and direction of transfer.

'Protons transferred from the balloon to the hair' is wrong because protons are fixed in the nucleus and never move between objects during friction in everyday situations.

If electrons left the balloon, the balloon would become positively charged (lost negative charge). But the balloon is negative, so this is backwards.

Neutrons are neutral — transferring them would not cause any charge difference. Neutrons also do not transfer between objects by rubbing.

'Electrons transferred from the hair to the balloon' is correct — the balloon gained electrons (became negative) and the hair lost electrons (became positive).