Which bond type forms from end-to-end overlap along the bond axis?

Which bond type forms from end-to-end overlap along the bond axis?

• A. Pi bond
• B. Sigma bond
• C. Delta bond
• D. Phi bond

Answer: (B)

End-to-end overlap along the bond axis forms a sigma bond. When orbitals overlap directly along the line between the two nuclei, electron density concentrates along that internuclear axis, creating a strong, head-on bond that holds the atoms together. This orientation is typical for single bonds and even the first bond in multiple bonds. In contrast, pi bonds come from sideways overlap of p orbitals above and below the bond axis, giving electron density that lies above and below the line and restricting rotation. Delta and phi bonds are higher-order, involving more complex d-orbital interactions and aren’t the result of end-to-end overlap along the axis.

End-to-end overlap along the bond axis forms a sigma bond. When orbitals overlap directly along the line between the two nuclei, electron density concentrates along that internuclear axis, creating a strong, head-on bond that holds the atoms together. This orientation is typical for single bonds and even the first bond in multiple bonds. In contrast, pi bonds come from sideways overlap of p orbitals above and below the bond axis, giving electron density that lies above and below the line and restricting rotation. Delta and phi bonds are higher-order, involving more complex d-orbital interactions and aren’t the result of end-to-end overlap along the axis.