Which of the following reactions occurs easily in ethylene?

"The negative part of the addendum adds on to the carbon atom linked with the least number of hydrogen atoms." This statement is called:

Conjugate double bond is present in

When $2-$butyne is treated with $H_2/$ Lindlar's catalyst,compound $X$ is produced as the major product and when treated with $Na/liq. NH_3$ it produces $Y$ as the major product. Which of the following statements is correct?

What is the product formed by the reaction of propene with $Br_2$ in $CCl_4$?

The number of alkene isomers with the molecular formula $C_4H_8$ is ....