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Grade 12th passPhysical Chemistry

In Chemical Bonding , One Type Formation Of Covalent Bond Occurs By Overlapping Of Atomic Orbitals {Sigma} (s-s , s-p ,p-p ) ,Taking Z-Axis As Reference Axis , The Order Of Stability Is :[ p-p > s-p > s-s ]
And Stability Is Directly Proportional To Bond Strength/Bond Energy/BDE .
Example Of : s-s Bond [ H2 Molecule ]
: s-p Bond [ HF Molecule ]
: p-p Bond [F2 Molecule]
BUT
Order Of Bond Strength/Bond Energy/BDE Of These Molecules Is :
HF (556 KJ/mol) > H2 (436 KJ/mol) > F2 (126 KJ/mol)
i.e [ s-p > s-s > p-p ]

HOW IS IT POSSIBLE ?

Please Suggest Your Respective Answers .

Profile image of Arpit
11 Years agoGrade 12th pass
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2 Answers

Profile image of Sunil Kumar FP
ApprovedApproved Tutor Answer11 Years ago
her HF hs the highest bond dissociation energy because of two factors
(1)electronegativity difference
(2)hydrogen bonding
next consider the size factor sizo of H2<F2 molecule hence larger BDE
HERE don not consider the overlapping factor
Profile image of Arpit
11 Years ago
Thank You For Your Answer Sir , But According To Your ?Statement And Applies Chemistry :
“What Will Be The Answer Of The Question : Arrange The Following In Decreasing Order Of Stability ::   σs-s . σs-p ,  σp-p ?