Solid particles condensed from the gaseous state after metal is heated.

Solid particles condensed from the gaseous state after metal is heated.

• A. Dusts
• B. Vapors
• C. Smokes
• D. Fumes

Answer: (D)

Solid particles formed when metal vapors condense as they cool are called fumes. When metal is heated enough to vaporize, atoms enter the gas phase. As those metal vapors rise into cooler air, they condense into extremely fine solid particles. These fumes are typically much smaller than dusts and behave as a fine aerosol that can be inhaled deeply, posing respiratory hazards in metalworking and welding. They’re different from dusts (solid particles produced by mechanical processes), vapors (the gaseous state of a substance), and smokes (particulates produced by combustion of organic material).

Solid particles formed when metal vapors condense as they cool are called fumes. When metal is heated enough to vaporize, atoms enter the gas phase. As those metal vapors rise into cooler air, they condense into extremely fine solid particles. These fumes are typically much smaller than dusts and behave as a fine aerosol that can be inhaled deeply, posing respiratory hazards in metalworking and welding. They’re different from dusts (solid particles produced by mechanical processes), vapors (the gaseous state of a substance), and smokes (particulates produced by combustion of organic material).