Question

sublimation is when a solid gains energy and becomes a gas, skipping the change to liquid. sublimation occurs when heat increases. it causes the particles to move so fast that they separate and become a gas. examples of sublimation include dry ice, freeze - drying, and mothballs. dry ice is solid carbon dioxide (co2) that does not melt into a liquid at room temperature; it sublimates into a gas. foods that are freeze - dried remove water from frozen foods without the water ever becoming liquid, going straight to water vapor. mothballs used to be made of a chemical called naphthalene, which sublimated at room temperature. this caused mothballs to decrease in size over time. what is the best definition of sublimation? it is when a solid becomes a gas. it is when a gas becomes a liquid. it is when a liquid becomes a solid.

Explanation:

Sublimation is the process where a solid directly transitions to a gas without passing through the liquid - state. This is clearly stated in the provided text and illustrated with examples like dry - ice, freeze - drying, and mothballs.

Answer:

It is when a solid becomes a gas.