Question

Identify the type of overlap present in H-F molecule. Explain diagrammatically.

Answer 1

s–p σ overlap:

1. In this type of overlap one half-filled s orbital of one atom and one half-filled p orbital of another orbital overlap along the internuclear axis.
   e.g. Formation of HF molecule by s–p overlap:
   Hydrogen atom (Z = 1) has electronic configuration: 1s¹ and fluorine atom (Z = 9) has electronic configuration 1s² 2s² \[\ce{2p^2_{{x}}}\] \[\ce{2p^2_{{y}}}\] \[\ce{2p^1_{{z}}}\]. During the formation of HF molecule, half-filled 1s orbital of hydrogen atom overlaps coaxially with half-filled 2p_z orbital of fluorine atom with opposite electron spin and an s–p σ bond is formed.
2. Diagram: