Question

Out of the following which posses delocalized chemicalbond
(1)- ch2=ch-ch=ch2 ,(2)- ch2=ch-ch2-ch=ch2

Answer 1

In organic chemistry, delocalization of electrons refers to π-bonding in a conjugated system.
‘a conjugated system is a molecular entity whose structure may be represented as a system of alternating
single and multiple bonds: e.g. CH 2 =CH–CH=CH 2 ’
Source: IUPAC Goldbook (https://goldbook.iupac.org/html/C/C01267.html)