Ionic compounds are generally hard, but brittle. It takes a large amount of mechanical force, such as striking a crystal with a hammer, to force one layer of ions to shift relative to its neighbor. ... The repulsive forces between like-charged ions cause the crystal to shatter.

Why are ionic compounds are brittle?

-The ionic solids are hard and brittle because the ions in ionic solids are held in a lattice due to the electrostatic forces of attraction in cations and anions as well as the repulsion with the like charges. ... Because the ionic solids are localized, these solids tend to be stiff and brittle like covalent solids.

Are covalent compounds brittle?

Mechanical properties: Ionic compounds tend to be hard and brittle while covalent compounds tend to be softer and more flexible.