No. Atoms can gain and lose electrons but seldom gain or lose protons.
gain
Argon is a Noble Gas. Thus it does not lose or gain electrons.
Gain or lose
If the chemical bond is ionic, an electron is gained or lost. If it is covalent, the electron is shared equally; if it is polar covalent, the electron is shared unequally. If the bond is intermolecular, no parts of the atom are actually shared, gained, or lost; the atom itself is simply attracted to other atoms.
Beryllium lose electrons (2).
The electro negativity of O is higher. So Beryllium loses 2 electrons.
Beryllium will lose 2 electrons to satisfy the octet rule (to fill its outer shell).
Beryllium has the electronic configuration 2, 2, so it is likely to lose two electrons, giving it the Helium configuration. However, in practice, beryllium compounds have a high degree of covalent character as the beryllium ion is small and very polarising.
OVER 9000
Beryllium would tend to lose its two electrons when forming a bond because it is easier to lose its two valence electrons rather than gain an additional five in order to obtain a full outer shell.
No. Atoms can gain and lose electrons but seldom gain or lose protons.
Covalent bonds do not gain or lose electrons, but rather share electrons.
It needs to gain 3 electrons than to lose 5 electrons. So phosphorus has to gain 3 electrons.
Lose
When atoms lose or gain electrons, they form ions. These are charged particles.
Se will gain electrons