Answer
Both ionic compounds and covalent compounds are hard, have high melting point, and are poor conductors of heat and electricity. But ionic compounds dissolve in water to produce ions, whereas elemental boron is insoluble in water. So, it must be a covalent compound.
Work Step by Step
Both ionic compounds and covalent compounds are hard, have high melting point, and are poor conductors of heat and electricity. But ionic compounds dissolve in water to produce ions, whereas elemental boron is insoluble in water. So, it must be a covalent compound.
