Why magnesium oxide is a solid at room temperature?

Magnesium oxide (MgO) is a solid at room temperature due to its ionic bonding and high lattice energy. The strong electrostatic forces between the positively charged magnesium ions and the negatively charged oxide ions result in a rigid and stable crystal lattice structure. This arrangement requires a significant amount of energy to break apart, which is not available at room temperature, thereby maintaining its solid state.