Question

what is isomers ? and its example ?

Answer 1

Compounds having same molecular formula but different structural formula are called isomers.
for eg:- n butane, neo pentane

Answer 2

An isomer (/ˈaɪsəmər/; from Greek ἰσομερής, isomerès; isos = "equal", méros = "part") is a molecule with the same molecular formula as another molecule, but with a different chemical structure. That is, isomers contain the same number of atoms of each element, but have different arrangements of their atoms.