What type of bond forms when atoms share electrons?

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

Answer: (C)

The correct answer is that a covalent bond forms when atoms share electrons. In a covalent bond, two or more atoms come together and share pairs of electrons in order to achieve stability, typically by completing their outer electron shells. This sharing of electrons allows each atom involved to attain a full valence shell, which is often associated with increased chemical stability.

Covalent bonds can be found in various molecules, including water (H2O) and carbon dioxide (CO2), where the atoms involved share electrons to achieve the desired electron configuration. Depending on the electronegativity of the atoms involved, covalent bonds can be classified as either non-polar (equal sharing of electrons) or polar (unequal sharing of electrons), but the fundamental characteristic of a covalent bond remains the sharing of electrons.

Understanding the nature of covalent bonds is fundamental in chemistry, as they are pivotal in the formation of most biological molecules and dictate many of their properties. Other bond types, such as ionic, hydrogen, and metallic bonds, involve different interactions and mechanisms of electron transfer or attraction, distinguishing them from the electron-sharing characteristics of covalent bonds.