Butyl is not a specific molecule, but a prefix that indicates a four-carbon chain in a molecule.

Therefore, any molecule with "butyl" in its name contains four carbon atoms.

For example:

* Butyl alcohol (C4H9OH) has four carbons.

* Butane (C4H10) has four carbons.

* Butyl acetate (C6H12O2) has four carbons in the butyl group.