The correct option is **C. Nonpolar covalent bond**. ### Explanation of the Correct Answer A **nonpolar covalent bond** is formed when two atoms share electrons equally. This means that the electrons are distributed evenly between the two atoms, resulting in no significant charge difference across the bond. 1. **Electron Sharing**: In a nonpolar covalent bond, the two atoms involved have similar electronegativities. Electronegativity is a measure of how strongly an atom attracts electrons in a bond. When two atoms with similar electronegativities bond, they pull on the shared electrons with equal strength, leading to an equal sharing of electrons. 2. **Balanced Distribution of Charge**: Because the electrons are shared equally, there is no partial positive or negative charge on either atom. This results in a balanced distribution of electrical charge, which is characteristic of nonpolar covalent bonds. 3. **Examples**: Common examples of molecules with nonpolar covalent bonds include diatomic molecules like \( \text{H}_2 \) (hydrogen gas), \( \text{N}_2 \) (nitrogen gas), and \( \text{O}_2 \) (oxygen gas). In these molecules, the two identical atoms share electrons equally, leading to a nonpolar bond. ### Explanation of Why Other Options Are Incorrect **A. Ionic bond**: - An ionic bond is formed when one atom donates an electron to another atom, resulting in the formation of charged ions. This occurs between atoms with significantly different electronegativities (e.g., sodium and chlorine). The electron transfer creates a positive ion and a negative ion, leading to an electrostatic attraction between them. This is not equal sharing, so it does not fit the definition of a nonpolar covalent bond. **B. Polar covalent bond**: - A polar covalent bond occurs when two atoms share electrons unequally due to a difference in electronegativity. In this case, one atom attracts the shared electrons more strongly than the other, resulting in a partial positive charge on one atom and a partial negative charge on the other. This unequal sharing leads to a dipole moment, which is not the case in a nonpolar covalent bond. **D. Hydrogen bond**: - A hydrogen bond is not a type of covalent bond at all; rather, it is a weak attraction between a hydrogen atom covalently bonded to a highly electronegative atom (like oxygen or nitrogen) and another electronegative atom. Hydrogen bonds are important in biological systems (e.g., in water and DNA) but do not involve the sharing of electrons between atoms in the way that covalent bonds do. ### Summary of Key Points - **Nonpolar covalent bonds** involve equal sharing of electrons between two atoms with similar electronegativities. - **Ionic bonds** involve the transfer of electrons and the formation of charged ions. - **Polar covalent bonds** involve unequal sharing of electrons, leading to partial charges. - **Hydrogen bonds** are weak attractions between molecules and do not involve electron sharing. This understanding of bond types is crucial for grasping the behavior of molecules in chemical reactions and interactions.