Which group includes mercury, lead, and arsenic?

• A. Heavy metals
• B. Nutrients
• C. Organic solvents
• D. Gases

Answer: (A)

Heavy metals are toxic elements with high atomic weights and metallic properties. Mercury, lead, and arsenic fit this group because they are elements that persist in the environment, can accumulate in living tissues, and cause serious health problems even at low exposure. They’re not nutrients, since they are not essential for life. They’re not organic solvents, which are carbon-based liquids used to dissolve other substances. And while mercury vapor is a gas, these elements are most commonly discussed as a group of metals/metalloids in pollution contexts due to their persistence and toxicity. Arsenic is technically a metalloid, but it’s routinely categorized with heavy metals in environmental toxicology because of its similar toxic behavior and environmental impact.