Tetrasubstituted Trisubstituted Disubstituted Monosubstituted R R H R R R R C2004 Thomson-Brooks/Cole The observed stability order of alkenes is due to Antibonding C-C T orbital (unfilled) ■hyperconjugation-a Bonding C-Ho orbital (filled) stabilizing interaction between the unfilled antibonding C=Cπbond orbitals and a filled C-Ho bond orbital on a neighbouring substituent The observed stability order of alkenes is due to „ hyperconjugation – a stabilizing interaction between the unfilled antibonding C=C π bond orbitals and a filled C-H σ bond orbital on a neighbouring substituent