What is the shape of the methyl carbocation,$\overset{\oplus}{C}H_3$?

For the following bond cleavages,use curved-arrows to show the electron flow and classify each as homolysis or heterolysis. Identify the reactive intermediate produced as free radical,carbocation,or carbanion.

Which of the following intermediates has a complete octet around the carbon atom?

Among the following carbocations:
$(I)$ $Ph_{2}\stackrel{+}{C} CH_{2} Me$
$(II)$ $Ph CH_{2} CH_{2} \stackrel{+}{C} HPh$
$(III)$ $Ph_{2} CH \stackrel{+}{C} HMe$
$(IV)$ $Ph_{2} C(Me) \stackrel{+}{C} H_{2}$
The order of stability is:

Explain why $((CH_3)_3C)^+$ is more stable than $(CH_3CH_2)^+$ and $(CH_3)^+$ is the least stable carbocation.

Provide four formulas of carbocations.