Like most metals, gold loses electrons when forming compounds.
It also depends on the oxidation state. +1 or +3 are most common.
Gold has a tendency to lose electrons in a chemical reaction, which is why it is known as a "noble metal." This property makes gold less reactive than other metals and contributes to its resistance to corrosion.
Lose
When atoms lose or gain electrons, they form ions. These are charged particles.
Se will gain electrons
Lose electrons is oxidation. To gain electrons is reduction.
Gold would lose electrons to form an ionic bond. As a metal, gold has a tendency to donate electrons, resulting in a positively charged ion (cation). This electron loss allows gold to bond with nonmetals, which typically gain electrons to form negatively charged ions (anions). The electrostatic attraction between these oppositely charged ions forms the ionic bond.
Silicon (Si) can gain or lose 4 electrons. It can either gain 4 electrons to have a stable octet configuration or lose 4 electrons to achieve a stable configuration.
If you mean Metals... No, they do not gain electrons, they actually lose electrons because it is a lot easy for them to lose them so they can gain stability much faster.
it loses electrons
Atoms typically do not lose protons because that would change the identity of the element. Instead, atoms can lose or gain electrons to form ions with a different charge. Protons are not generally lost by atoms in chemical reactions.
Electrons
Selenium may lose 2, 4 or 6 electrons and may gain 2 electrons.