Octane (C8H18) is a straight-chain alkane comprising eight carbon atoms. It is a primary constituent in gasoline and is employed as a reference standard in the octane rating scale, which measures a fuel's ability to resist engine knocking or pinging. As a liquid at room temperature and atmospheric pressure, octane is less dense than water and possesses a characteristic hydrocarbon odor. In the optical domain, octane's properties can be utilized in certain specialized settings. While it's not highly reactive, safety precautions should be followed when handling octane, particularly due to its flammability.