Due to the presence of an unpaired electron,free radicals are

The decreasing order of stability of the given carbocations is

Consider the following compound $(X)$:
$H-C \equiv C-CH_2-CH(CH_3)-CH_3$
The most stable and least stable carbon radicals,respectively,produced by homolytic cleavage of the corresponding $C-H$ bond are:

Arrange the following carbanions in the decreasing order of their stability:
$(1) CH_3-CH_2^-, (2) CH_2=CH^-, (3) HC \equiv C^-$

Match the ions given in Column-$I$ with their nature given in Column-$II$.

Column-$I$	Column-$II$
$A$. $CH_3-O^{+}=CH-CH_3$	$1$. Stable due to resonance
$B$. $F_3C^{+}$	$2$. Destabilised due to inductive effect
$C$. $(CH_3)_3C^{-}$	$3$. Stabilised by hyperconjugation
$D$. $CH_3-CH^{+}-CH_3$	$4$. $A$ secondary carbocation

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