You can prevent a mask from fogging underwater by lowering the?

You can prevent a mask from fogging underwater by lowering the?

• A. Temperature
• B. Humidity
• C. Oxygen level
• D. Surface tension

Answer: (D)

Fogging happens when water vapor condenses on the inside of the mask lens and forms tiny droplets that scatter light. How those droplets form depends on surface tension. When surface tension is lowered, water wets the surface more easily and spreads into a thin film rather than bead-like droplets. That thin film is optically clearer, so you see through the mask better. Anti-fog agents work by lowering surface tension at the lens, promoting that even film instead of droplets. The other factors aren’t as directly tied to the fogging mechanism: changing temperature can change condensation but usually makes fogging worse if the lens is cooler, humidity affects how much water vapor is available but isn’t the direct control for droplet formation, and oxygen level doesn’t influence fogging.

Fogging happens when water vapor condenses on the inside of the mask lens and forms tiny droplets that scatter light. How those droplets form depends on surface tension. When surface tension is lowered, water wets the surface more easily and spreads into a thin film rather than bead-like droplets. That thin film is optically clearer, so you see through the mask better.

Anti-fog agents work by lowering surface tension at the lens, promoting that even film instead of droplets. The other factors aren’t as directly tied to the fogging mechanism: changing temperature can change condensation but usually makes fogging worse if the lens is cooler, humidity affects how much water vapor is available but isn’t the direct control for droplet formation, and oxygen level doesn’t influence fogging.