What is the process by which a solid transforms directly into gas?

Sublimation is the process by which a solid is converted straight into a gas without passing through the liquid phase.

Sublimation is commonly observed in certain substances, such as:

Dry Ice: Dry ice sublimes at -78.5°C under standard atmospheric pressure, producing carbon dioxide gas.

Naphthalene: Naphthalene mothballs sublimate slowly at room temperature,

Iodine Crystals: Solid iodine sublimes at temperatures above 114°C under standard atmospheric pressure.