Magnesium oxide (MgO) is an ionic compound. This classification stems from the nature of the bond formed between the magnesium and oxygen atoms.
In ionic bonding, one atom donates an electron to another atom, leading to the formation of ions. Magnesium, which is located in group 2 of the periodic table, has two electrons in its outermost shell. To achieve a stable electron configuration, magnesium tends to lose these two electrons, resulting in a positively charged ion (Mg2+).
On the other hand, oxygen, found in group 16, has six electrons in its outermost shell and needs two more electrons to reach a stable configuration. Therefore, it gains two electrons from magnesium, becoming a negatively charged ion (O2-). The opposite charges of these ions lead to a strong electrostatic attraction between them, which is characteristic of ionic compounds.
Thus, due to the transfer of electrons from magnesium to oxygen and the resulting ionic bond, magnesium oxide is classified as an ionic compound.