How many electrons does a barium ion have? 56 8 38 2 54
The correct answer and explanation is:
The correct answer is 54.
Barium (Ba) has an atomic number of 56, meaning it normally has 56 protons and, in a neutral atom, also 56 electrons. However, when a barium ion is formed, it tends to lose two electrons because of its position in the alkaline earth metals group. This group includes elements like magnesium and calcium, which typically form 2+ ions by losing two electrons to achieve a stable electron configuration, similar to that of the nearest noble gas.
Barium, with its electron configuration of [Xe] 6s², loses its two 6s electrons when it forms a Ba²⁺ ion. The resulting ion has 56 protons (since the number of protons doesn’t change in an ion), but only 54 electrons. This loss of electrons leads to a net positive charge of +2 for the ion (since there are 2 more protons than electrons).
Therefore, a Ba²⁺ ion has 54 electrons in total. The process of forming a positive ion is essential for understanding how elements stabilize themselves by achieving a noble gas configuration, which is the ultimate goal in ionic bonding and reactions. By losing electrons, barium achieves the electron configuration of xenon (Xe), a stable noble gas, thereby minimizing its energy and maximizing its stability.
In summary, a barium ion (Ba²⁺) has 54 electrons because it has lost 2 electrons from its neutral atomic state, leaving it with a charge of +2.