Ethylene oxide, also known as oxirane, is an organic compound with the molecular formula C2H4O. Its structure consists of a three-membered ring containing two carbon atoms and one oxygen atom. The functional groups present in ethylene oxide are:1. Epoxy group: The three-membered ring containing an oxygen atom is called an epoxy or oxirane group. This group is highly strained due to the small ring size, which makes it highly reactive.The reactivity of ethylene oxide towards nucleophiles can be explained as follows:1. Strain release: The three-membered epoxy ring in ethylene oxide is highly strained due to the small ring size and the presence of an oxygen atom. This strain makes the molecule highly reactive, as breaking the ring can release the strain and lead to a more stable product.2. Electrophilic nature of the epoxy group: The oxygen atom in the epoxy group is more electronegative than the carbon atoms, which results in a partial positive charge on the carbons. This makes the carbons in the epoxy group highly susceptible to attack by nucleophiles.When a nucleophile attacks one of the carbons in the epoxy ring, the ring opens, and a new bond is formed between the nucleophile and the carbon. This reaction is called nucleophilic ring-opening of epoxides. The oxygen atom in the epoxy group can also act as a leaving group, which further facilitates the nucleophilic attack.In summary, the functional groups present in ethylene oxide are the epoxy or oxirane group. The reactivity of ethylene oxide towards nucleophiles can be attributed to the strain release upon ring-opening and the electrophilic nature of the epoxy group.