Questions: Ionic and Covalent Bonds: An Introduction

Question 1

Which type of bond typically forms between a metal and a nonmetal?

• A. Covalent bond
• B. Ionic bond
• C. Metallic bond
• D. Hydrogen bond

Answer: (B)

When a metal (which tends to lose electrons) bonds with a nonmetal (which tends to gain electrons), electrons are transferred from the metal to the nonmetal, forming positively and negatively charged ions. The attraction between these opposite charges creates an ionic bond.

Question 2

Covalent bonds form when atoms share electrons.

• T. True
• F. False

Answer: True

In a covalent bond, two atoms (usually nonmetals) each contribute electrons to a shared pair. Neither atom completely gives up or takes the electrons — they share them, which allows both atoms to achieve a more stable electron arrangement.

Question 3

Explain why table salt (NaCl) has a much higher melting point than water (H2O).

Model answer: Table salt is an ionic compound with strong attractions between many ions in a crystal lattice, which requires a lot of energy to break apart. Water is a covalent compound with weaker attractions between its molecules.

In NaCl, every sodium ion is surrounded by chloride ions and vice versa, creating a rigid crystal lattice held together by strong electrostatic forces throughout the entire structure. Melting requires breaking many of these attractions simultaneously. Water molecules are held together by weaker forces between molecules, so less energy is needed to separate them.