State Markovnikov's rule and explain it with an example.

(N/A) Markovnikov's rule states that when an unsymmetrical reagent (like $HX$) adds to an unsymmetrical alkene,the negative part of the addendum attaches itself to the carbon atom of the double bond that possesses the lesser number of hydrogen atoms.
Example: Addition of $HBr$ to propene $(CH_3-CH=CH_2)$.
When $HBr$ reacts with propene,two products are possible:
$1$. $CH_3-CH(Br)-CH_3$ ($2$-Bromopropane) - Major product
$2$. $CH_3-CH_2-CH_2Br$ ($1$-Bromopropane) - Minor product
According to Markovnikov's rule,the $Br^-$ ion (negative part) attaches to the central carbon atom (which has only one $H$ atom),leading to the formation of $2$-Bromopropane as the major product. This reaction proceeds via an electrophilic addition mechanism.