1-Butene and 2-Butene are isomers because they have the same molecular formula (C4H8) but differ in the arrangement of atoms within the molecule, leading to different structural formulas.
In 1-Butene, the double bond is located at the first carbon atom in the chain. Its structural formula is CH2=CH-CH2-CH3. On the other hand, in 2-Butene, the double bond is located at the second carbon atom in the chain, giving it the structural formula CH3-CH=CH-CH3.
These differences in the placement of the double bond result in unique physical and chemical properties for each isomer, despite having the same number of carbon and hydrogen atoms.
