Why are ionic compounds solid at room temperature?
Ionic compounds are formed when atoms of different charges (i.e. positive and negative ions) come together and form ionic bonds. These ionic bonds are typically very strong due to the high attractive forces holding the positively and negatively charged ions together (called electrostatic forces of attraction).
Because ionic compounds are formed by alternating positive and negative ions, and because they are all held together with these strong electrostatic forces, the oppositely charged ions pack tightly with each other and form a crystal lattice structure that is extremely hard to break.
Thus, at normal room temperatures, the strength of these connections are much stronger than the kinetic energy of the ions, and so they cannot break away from each other! Instead, the ions are held rigidly together in their organized crystal lattice structure, and that is why they are solid under normal conditions.