Francium lose one electron to form the cation Fr+.
Compounds will gain or lose electrons in order to reach a more stable state, ideally a full valence shell.
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.
Polonium will neither gain nor lose electron. it will prefer to form covalent compounds by sharing of electrons.
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
Francium has the lowest electronegativity and fluorine the highest.
An element's most likely oxidation state is often related to its valence electrons because elements tend to gain or lose electrons to achieve a stable electron configuration. The number of valence electrons an element has can determine how many electrons it will gain or lose to reach a full or empty outer shell, resulting in a specific oxidation state.
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.