Explain why `(CH_(3))_(3)overset(+)(C )` is more stable than `CH_(3)overset(+)(C )H_(2) and overset(+)(C )H_(3)` is the least stable cation.

Explanation

Hyperconjugation interaction in `(CH_(3))_(3)overset(+)(C)` is greater than in `CH_(3)overset(+)(C)H_(2)` as the `(CH_(3))_(3)overset(+)(C )` has nine C-H bonds. In `overset(+)(C)H_(3)`, vacant p orbital is perpendicular to the plane in which C-H bonds lie, hence cannot overlap with it. Thus, `overset(+)(C)H_(3)` lacks hyperconjugative stability.