Chlorine $\left(Cl^{17}\right)$ free radical contains how many electrons around the nucleus?

The stability of carbanions follows the order:
$I: CH_3CH_2CH_2\bar{C}H_2$
$II: CH_3\bar{C}HCH_2CH_3$
$III: (CH_3)_3\bar{C}$
$IV: CH_3\bar{C}(Ph)CH_2CH_3$

The incorrect statement about carbene $(CH_2)$ is:

Consider the following carbocations:
$I. C_6H_5CH_2^+$
$II. CH_2=CH^+$
$III. CH_3-CH^+(CH_3)$
$IV. CH_3-CH_2^+$
$V. HC \equiv C^+$
Arrange the above carbocations in the order of decreasing stability.

Choose the correct statement regarding the formation of carbocations $A$ and $B$ given:
$CH_3-CH_2-CH=CH_2 + HBr \to CH_3-CH_2-CH_2-CH_2^+ + Br^-$ $(A)$
$CH_3-CH_2-CH=CH_2 + HBr \to CH_3-CH_2-CH^+-CH_3 + Br^-$ $(B)$

Which of the following carbocations is the most stable?