Which of the substances S8, CaCl2, SOCl2, NaF, CBr4, BrCl, LiF, and AsH3 contain bonds that are: (a) largely ionic? (b) nonpolar covalent? (c) polar covalent?

Verified step by step guidance

1. Step 1: Understand the types of chemical bonds. Ionic bonds form between metals and nonmetals, where electrons are transferred. Covalent bonds form between nonmetals, where electrons are shared. Polar covalent bonds have unequal sharing of electrons, while nonpolar covalent bonds have equal sharing.
2. Step 2: Identify the substances with ionic bonds. Look for compounds formed between metals and nonmetals. For example, CaCl2 and NaF are formed from a metal and a nonmetal, indicating largely ionic bonds.
3. Step 3: Identify the substances with nonpolar covalent bonds. Look for molecules with similar or identical nonmetals. For example, S8 and CBr4 involve nonmetals with similar electronegativities, indicating nonpolar covalent bonds.
4. Step 4: Identify the substances with polar covalent bonds. Look for molecules with different nonmetals where there is a significant difference in electronegativity. For example, SOCl2, BrCl, and AsH3 have polar covalent bonds due to the difference in electronegativity between the atoms.
5. Step 5: Consider the electronegativity differences. Use the periodic table to compare electronegativities and confirm the type of bond in each substance. Larger differences indicate ionic or polar covalent bonds, while smaller differences indicate nonpolar covalent bonds.

Key Concepts

Ionic Bonds

Ionic bonds form between atoms with significantly different electronegativities, typically between metals and nonmetals. In these bonds, one atom donates an electron to another, resulting in the formation of charged ions. The electrostatic attraction between these oppositely charged ions creates a strong bond. Substances like CaCl2 and LiF exhibit ionic characteristics due to the large difference in electronegativity between their constituent elements.

Covalent Bonds

Covalent bonds occur when two atoms share electrons, typically between nonmetals. The nature of the bond can vary based on the difference in electronegativity between the atoms involved. If the electronegativity difference is small, the bond is considered nonpolar covalent, while a moderate difference results in polar covalent bonds. For example, SOCl2 and AsH3 contain polar covalent bonds due to the unequal sharing of electrons.

Electronegativity

Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond. The difference in electronegativity between two bonded atoms determines the bond type: a large difference indicates ionic bonding, a small difference indicates nonpolar covalent bonding, and a moderate difference indicates polar covalent bonding. Understanding electronegativity helps predict the behavior of substances like NaF and CBr4 in terms of bond character.