To understand the Lewis dot structure for magnesium sulfide (MgS), we first need to identify the valence electrons of the constituent atoms.
Magnesium (Mg) is in group 2 of the periodic table and has 2 valence electrons. Sulfur (S) is in group 16 and has 6 valence electrons. When magnesium and sulfur combine to form magnesium sulfide, magnesium donates its 2 electrons to sulfur, allowing both elements to achieve a stable electron configuration.
In the Lewis dot structure, magnesium is represented with no dots around it since it loses its 2 valence electrons, becoming a positively charged ion (Mg2+). Sulfur, on the other hand, gains those 2 electrons, leading to 8 valence electrons around it, which is depicted as having 8 dots (2 paired and 4 unpaired) around it, giving it a negatively charged ion (S2-).
The Lewis dot structure can be illustrated as follows:
Mg⁺ :S:
In summary, the Lewis dot structure for magnesium sulfide highlights the transfer of electrons from magnesium to sulfur, resulting in the formation of a stable ionic compound.