The stability order can be explained by hyper conjugation and also by +I effect of alkyl groups

The stability order of alkyl free radicals can be explained by hyperconjugation

The structure of benzene can also be explained by

Stability of alkenes, carbocations, alkyl free radicals, orienting effect of alkyl groups in aromatic ring, unexpected bond lengths in some molecules, etc. can be explained by hyperconjugation

Carbocations are species in which central carbon carries positive charge. If the charge on the carbocations gets cocentrated or lo-calized the carbocation becomes unstable. The two factors which account for stability of carbocations are inductive effect and hyper conjugation (no bond resonance). Inductive effect is minor factor and hyper conjugation is major factor. Hybridisation of carbon in carbocation is

Carbocations are species in which central carbon carries positive charge. If the charge on the carbocations gets cocentrated or lo-calized the carbocation becomes unstable. The two factors which account for stability of carbocations are inductive effect and hyper conjugation (no bond resonance). Inductive effect is minor factor and hyper conjugation is major factor. Which is most stable carbocation

Carbocations are species in which central carbon carries positive charge. If the charge on the carbocations gets cocentrated or lo-calized the carbocation becomes unstable. The two factors which account for stability of carbocations are inductive effect and hyper conjugation (no bond resonance). Inductive effect is minor factor and hyper conjugation is major factor. n-propyl carbocation rearranges to isopropyl carbocation by shift of