The correct option is **C. Nonpolar covalent bond**. ### Explanation of the Correct Answer 1. **Definition of Bond Types**: - **Ionic Bond**: This type of bond occurs when one atom donates an electron to another atom, resulting in the formation of charged ions. The electrostatic attraction between these oppositely charged ions forms the bond. This typically happens between metals and nonmetals. - **Polar Covalent Bond**: In this bond, two atoms share electrons unequally. This occurs when the atoms involved have different electronegativities, leading to a partial positive charge on one atom and a partial negative charge on the other. - **Nonpolar Covalent Bond**: This bond forms when two atoms share electrons equally. This typically occurs between atoms of the same element or between different elements that have similar electronegativities. - **Metallic Bond**: This bond is characterized by a 'sea of electrons' that are free to move around, allowing metals to conduct electricity and heat. It involves the attraction between positively charged metal ions and the delocalized electrons. 2. **Why Nonpolar Covalent Bond is Correct**: - When two atoms share electrons equally, it means that neither atom has a stronger pull on the shared electrons than the other. This equal sharing results in a nonpolar covalent bond. - A classic example of a nonpolar covalent bond is the bond between two hydrogen atoms (H₂). Each hydrogen atom has the same electronegativity, so they share the electrons equally, resulting in a stable molecule without any charge separation. ### Explanation of Why Other Options are Incorrect - **A. Ionic Bond**: This option is incorrect because ionic bonds involve the transfer of electrons rather than sharing. In ionic bonding, one atom loses electrons (becoming positively charged) while the other gains electrons (becoming negatively charged). This is not the case when electrons are shared equally. - **B. Polar Covalent Bond**: This option is also incorrect because polar covalent bonds involve unequal sharing of electrons. In a polar covalent bond, one atom has a higher electronegativity than the other, leading to an unequal distribution of electron density. This results in partial charges on the atoms, which is not the case in a nonpolar covalent bond. - **D. Metallic Bond**: This option is incorrect as well because metallic bonds do not involve the sharing of electrons between two distinct atoms. Instead, they involve a collective sharing of electrons among a lattice of metal atoms, which is fundamentally different from the equal sharing seen in nonpolar covalent bonds. ### Summary of Key Points - A **nonpolar covalent bond** is formed when two atoms share electrons equally. - This type of bond typically occurs between atoms of the same element or those with similar electronegativities. - In contrast, **ionic bonds** involve electron transfer, **polar covalent bonds** involve unequal sharing, and **metallic bonds** involve a delocalized electron sea. - Understanding the differences between these bond types is crucial for predicting molecular behavior and properties. By grasping these concepts, you will have a solid foundation for understanding chemical bonding in your studies.