Which of the following correctly distinguishes ionic bonding from covalent bonding and gives two characteristic properties of each type?

• A. Ionic bonding involves electron transfer and electrostatic attraction; covalent bonding involves electron sharing; Ionic: high melting points; conducts electricity when melted or dissolved. Covalent: lower melting points; poor conductors.
• B. Ionic bonds share electrons; Covalent involves transfer; both have high melting points.
• C. Ionic bonds form molecules; Covalent bonds form lattices; only ionic conduct electricity in solid state.
• D. Both are identical; no difference.

Answer: (A)

The key idea is how electrons are arranged and how that affects structure and properties. Ionic bonding comes from electrons being transferred from a metal atom to a nonmetal, creating oppositely charged ions that attract each other strongly and form a lattice. Covalent bonding comes from sharing electrons between atoms, creating molecules (or network structures) held together by those shared electrons.

That distinction helps explain the properties chosen. Ionic compounds have high melting (and boiling) points because the electrostatic forces between the many ions in the lattice are very strong, so a lot of energy is needed to break the lattice. They conduct electricity when melted or dissolved because the ions are free to move and carry charge. Covalent compounds, on the other hand, generally have lower melting points since the forces between molecules are weaker than the ionic lattice, and they are poor conductors because neutral molecules don’t provide free charge carriers.

Why the other statements don’t fit: mixing up electron transfer with sharing gets the bonding picture wrong, and assigning high melting points to covalent bonds isn’t generally true. Saying ionic compounds only conduct electricity in the solid state is incorrect (they conduct when molten or dissolved), and claiming covalent bonds form lattices or that both types are identical misses the fundamental differences in bonding and behavior.