Ethylene is a plant hormone. It has been used as a natural stimulant for growth ever since it was first used by the ancient Egyptians. It is the most popular carbon compound that is produced chemically. Ethylene is a hydrocarbon compound with the molecular formula of C2H4. It is a scented colorless gas with many properties that heavily impact fruit growth on many plants. Ethylene is produced by superheating hydrocarbon to a point where free radical reactions take place. Once plants are exposed to ethylene, fruits ripen quickly and many plant related functions are sped up. The fruit above was likely ripened with the use of ethylene.