Question

which were popular chemical compounds that were found to be effective insecticides during the 19th century?
sulfur and neon
lead and copper
pyrethrum and rotenone
magnesium and nickel

Explanation:

To determine the correct answer, we analyze each option:

• Sulfur (a non - metal) and neon (a noble gas) are not known as 19th - century insecticides. Neon is inert and has no insecticidal properties.
• Lead and copper are metals. While some lead and copper compounds have been used in other applications, they were not popular 19th - century insecticides.
• Pyrethrum (derived from chrysanthemums) and rotenone (a natural compound from plants) were widely recognized and used as effective insecticides during the 19th century.
• Magnesium and nickel are metals and do not have insecticidal properties.

Answer:

C. pyrethrum and rotenone