Final answer:
To name a halide according to the IUPAC system, identify the longest alkyl chain containing the halogen and use prefixes to denote the halogen. Without proper structural information, accurate naming and classification of the given halide as alkyl, allyl, benzyl, vinyl, or aryl halide are not possible.
Step-by-step explanation:
The molecule given in the question, CH₃CH, seems to be incomplete and potentially includes a typo, as it lacks a halogen and also does not form a complete chemical structure. Nevertheless, to name a halide according to the IUPAC system, one must find the longest carbon chain that includes the halogen, give the halogen a prefix (such as fluoro-, chloro-, bromo-, or iodo-), and number the carbon chain to give the halogen the lowest possible number.
For example, CH₃CH₂Br would be named 1-bromopropane. An alkyl halide is usually classified as primary (1°), secondary (2°), or tertiary (3°) depending on the number of carbon atoms connected to the carbon bearing the halogen.
Without the correct structure, it's unfeasible to provide an accurate IUPAC name or classify the halide as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl, or aryl halide. If we had, for instance, CH₃CH₂Cl, it would be named chloroethane and classified as a primary alkyl halide because the halogen (chlorine) is attached to a carbon that is also connected to just one other carbon.