Barium sulfide is an ionic compound formed by the transfer of electrons from barium to sulfur. To understand how this occurs, we can use a Lewis dot structure.
Barium (Ba) is an alkaline earth metal found in group 2 of the periodic table. It has two valence electrons that it readily loses to achieve a stable electron configuration. Sulfur (S), on the other hand, is a non-metal in group 16 and has six valence electrons. It needs two additional electrons to complete its outer shell and achieve stability.
In the Lewis dot structure, we represent the valence electrons as dots around the chemical symbol:
- Barium (Ba) has two dots representing its two valence electrons:
- Sulfur (S) has six dots representing its six valence electrons:
Ba: ••
S: ••••••
When barium reacts with sulfur, it transfers its two valence electrons to sulfur. This can be visualized as follows:
Before transfer:
Ba: •• S: ••••••
After transfer:
Ba: S: •••••• + ••
In the process, barium becomes a positively charged ion (Ba²⁺) and sulfur becomes a negatively charged ion (S²⁻). The result is the formation of the ionic bond between these two ions, leading to the chemical formula for barium sulfide, which is:
BaS
This formula indicates that one barium ion combines with one sulfide ion to form barium sulfide.