Which group in each pair has the highest priority? a) -CH_(3) or -CH_(2)CH_(3) b) -1 or -Br c) -CH_(3)Br or -CH_(2)CH_(2)Br

a) In the pair or , has the highest priority. This is because is a primary alkyl group, while is a secondary alkyl group. According to the IUPAC priority rules, primary alkyl groups have higher priority than secondary alkyl groups.b) In the pair or , has the highest priority. This is because is a halogen atom, while is not a valid chemical group. According to the IUPAC priority rules, halogen atoms have higher priority than non-halogen atoms.c) In the pair or , has the highest priority. This is because is a primary alkyl halide, while is a secondary alkyl halide. According to the IUPAC priority rules, primary alkyl halides have higher priority than secondary alkyl halides.