Which of the following compounds would you expect to have covalent bonds? (LO 2.20) (a) Na₂O (b) PBr₃ (c) CaBr₂ (d) MgS

Verified step by step guidance

1. Step 1: Understand that covalent bonds are formed when two nonmetals share electrons. This is in contrast to ionic bonds, which are formed when a metal and a nonmetal exchange electrons.
2. Step 2: Identify the type of elements in each compound. Sodium (Na) and Oxygen (O) in Na₂O are a metal and a nonmetal, respectively. Phosphorus (P) and Bromine (Br) in PBr₃ are both nonmetals. Calcium (Ca) and Bromine (Br) in CaBr₂ are a metal and a nonmetal, respectively. Magnesium (Mg) and Sulfur (S) in MgS are a metal and a nonmetal, respectively.
3. Step 3: Based on the types of elements in each compound, predict the type of bond. Na₂O, CaBr₂, and MgS are likely to have ionic bonds because they are composed of a metal and a nonmetal. PBr₃ is likely to have covalent bonds because it is composed of nonmetals only.
4. Step 4: Therefore, the compound that you would expect to have covalent bonds is PBr₃.

Key Concepts

Covalent Bonds

Covalent bonds are formed when two atoms share one or more pairs of electrons, typically between nonmetals. This type of bonding allows atoms to achieve a full outer shell of electrons, leading to greater stability. Compounds with covalent bonds often have lower melting and boiling points compared to ionic compounds and can exist as gases, liquids, or solids at room temperature.

Ionic vs. Covalent Compounds

Ionic compounds are formed through the transfer of electrons from one atom to another, resulting in the formation of charged ions that attract each other. In contrast, covalent compounds involve the sharing of electrons. Understanding the difference between these types of bonding is crucial for predicting the properties and behaviors of various compounds, including their solubility and conductivity.

Electronegativity

Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a bond. In general, nonmetals have higher electronegativities than metals, which influences whether a bond will be ionic or covalent. When two atoms with similar electronegativities bond, they are more likely to form covalent bonds, while a significant difference typically leads to ionic bonding.