Answer:
3. lost electrons.
Explanation:
An atom that has lost an electron is positively charged because the number of protons is now greater than the number of electrons in the atom.
If the number of protons and electrons are the same, the atom has no charge
If the protons > electrons, the atom becomes positively charged
If electrons > protons, the atom becomes negatively charged.
Atoms becomes charged by losing or gaining electrons.
