user: Question: What prefix has chemical class iodoalkane?
Columns: ['Chemical class', 'Group', 'Formula', 'Prefix', 'Suffix', 'Example']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['haloalkane', 'halo', 'RX', 'halo-', 'alkyl halide', 'Chloroethane (Ethyl chloride)']
SQL:

assistant: SELECT "Prefix" FROM "Table" WHERE "Chemical class" = 'iodoalkane';