What is the IUPAC name of the simplest alkene, C2H4?

The simplest alkene is C2H4, which consists of two carbon atoms and four hydrogen atoms. In organic chemistry, alkenes are defined as hydrocarbons that contain at least one double bond between carbon atoms. The presence of a double bond in the structure of C2H4 classifies it as an alkene.

The IUPAC naming convention for alkenes involves using the root name for the number of carbon atoms in the longest chain and adding the suffix "-ene" to indicate the presence of a double bond. Since C2H4 has two carbon atoms, the root name is derived from "eth-" which corresponds to two carbons. Thus, by adding "-ene" to "eth-", we arrive at "ethene" as the correct IUPAC name.

In contrast, the other choices represent either different types of hydrocarbons or incorrect structures. Ethane refers to C2H6, which is a saturated hydrocarbon (alkane) that only has single bonds between carbon atoms. Propen and butene refer to alkenes with three and four carbon atoms, respectively, which do not accurately represent the simplest alkene with two carbon atoms. Therefore, the correct name for the simplest alkene C2H