Two electrons
Barium has 2 valence electrons. It needs to give up these 2 electrons to achieve a noble gas electron configuration, specifically by having a filled outer shell like a noble gas.
Barium has 2 electrons in its outer shell. In order to achieve a noble gas electron configuration it needs to lose these 2 electrons. This will leave it with the same electron configuration as Xenon, a noble gas.
The noble gas electron configuration for barium is [Xe] 6s2.
Barium has 2 electrons in its outermost shell. To achieve a noble gas electron configuration similar to xenon, which has 8 electrons in its outermost shell, barium would need to give up 2 electrons. This would leave barium with a full outer shell and a stable electron configuration.
When barium becomes an ion, it typically loses two electrons to achieve a stable electron configuration, resulting in a barium ion with a charge of +2. This ion is represented as Ba²⁺. The loss of these two electrons allows barium to attain the same electron configuration as the nearest noble gas, xenon.
The condensed ground state electron configuration for Barium is [Xe] 6s^2. This indicates that Barium has a full inner electron shell (represented by the noble gas configuration of Xenon) and two electrons in the outermost 6s orbital.
Barium, with an atomic number of 56, needs to lose 2 electrons to achieve a stable electron configuration, similar to a noble gas. This is because barium will then have a filled outer electron shell, following the octet rule.
Silver (Ag) has 47 electrons. To achieve a pseudo-noble-gas electron configuration, silver would need to lose one electron to achieve a stable electron configuration that resembles a noble gas configuration like argon.
Two electrons are donated by Barium to an oxidant (nonmetal, eg. O2) by which barium gets oxidised.Ba --> Ba2+ + 2e-This is because Ba is in group 2 of the periodic system, belonging to the 'earth alkali' metals and so it has 2 electrons (2e-) in its valency (or outer) shell (2,8,18,18,8,2). Hence Ba2+ configuration is (2,8,18,18,8,-), with an empty (-) 6th shell (the 'P' shell) like Xenon.
Chlorine gains 1 electron to achieve the noble gas electron configuration of argon.
Losing an electron cesium has a noble gas configuration.
To achieve noble gas configuration, Bromine must gain one electron. In doing so, it obtains the electron configuration of Krypton. It's new complete electron configuration would be: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6.