Work out all possible structural isomeric alkenes corresponding to `C_(5)H_(10)` and also give their `IUPAC` names.
Strategy: Alkene isomers are deduced by writing the different `C` skeletons and then introducing the double bond at different locations. The possible skeletons are
`C-C-underset((I))C-C-C,C-underset((II))underset(C)underset(|)C-C-C,C-underset((III))underset(C )underset(|)overset(C )overset(|)C-C`

Explanation

First explore all the possibilities of placing the double bond for the straight-chain skeleton (I):
(i) `CH_(3)CH_(2)underset("Pent-1-ene")(CH_(2))CH=CH_(2)`
(ii) `CH_(3)CH_(2)underset("Pent-2-ene")(CH=)CHCH_(3)`
Next explore all the possibilities of positioning the double bond for the branched-chain skeleton(II):
(iii) `overset(4)(CH_(3))-^(3)underset(3-"Methylbut-1-ene")(overset(CH_(3))overset(|)(CH)-overset(2)C=overset(1)(C)H_(2))`
(iv) `overset(1)CH_(3)-underset(2-"Methylbut-2-ene")(underset(CH_(3))underset(|)overset(2)(CH)=overset(3)CH-overset(4)CH_(3)`
(v)`overset(1)CH_(2)=underset(2-"Methybut-1-ene")(underset(CH_(3))underset(|)overset(2)(CH)-overset(3)CH-overset(4)CH_(3)`
The " central " `C`" atom " of (III)" is a quarternary "`C` "atom and cannot form a double bond to give an alkane".