Question

chalk is an ionic compound. which is a property of all ionic compounds that makes chalk particularly useful for writing on a chalkboard?
○ a high melting point
○ hardness and brittleness
○ inability to dissolve in water
○ a multicolored appearance

Explanation:

Ionic compounds have strong electrostatic forces between ions. This leads to high melting points. However, chalk's hardness and brittleness (due to ionic lattice structure) make it useful for writing on a chalkboard. A multicolored appearance is not a general ionic compound property. Ionic compounds can dissolve in water (opposite of the option). High melting point is a general ionic property but not what makes chalk useful for writing.

Answer:

hardness and brittleness