Here's a breakdown of what happens:
* Energy Input: Sublimation requires an input of energy, typically in the form of heat. This energy causes the molecules within the solid to vibrate more rapidly.
* Breaking Bonds: As the molecules vibrate faster, they overcome the attractive forces holding them together in the solid state. These forces are called intermolecular bonds.
* Direct Transition: The molecules transition directly from a tightly packed, ordered arrangement in the solid state to a more spread out, random arrangement in the gaseous state.
* Gas Formation: The molecules move freely and independently, forming a gas.
Examples of Sublimation:
* Dry Ice: Solid carbon dioxide (dry ice) sublimates directly into carbon dioxide gas at room temperature.
* Mothballs: Mothballs, often made of naphthalene, slowly sublimate over time, releasing a vapor that repels moths.
* Frozen Water (Under Certain Conditions): Under low pressure conditions, like in a vacuum chamber, ice can sublimate directly into water vapor.
Key Points:
* Sublimation is a physical change, not a chemical change. The chemical composition of the substance remains the same.
* Sublimation is an endothermic process, meaning it absorbs heat from the surroundings.
* The reverse process of sublimation, where a gas turns directly into a solid, is called deposition.
