Why Sublimation is a Physical Change?

Sublimation is a physical change because it changes physical state of a substance without altering its chemical composition.

During sublimation, the molecules absorb energy and gain enough kinetic energy to break the bonds that hold them together in the solid state. As a result, the molecules separate and become a gas, without going through the liquid phase.

Explanation with examples

One example of sublimation that you may be familiar with is dry ice. Dry ice is solid carbon dioxide, which sublimes at a temperature of -78.5 degrees Celsius (-109.3 degrees Fahrenheit). When dry ice is exposed to air, it sublimes into carbon dioxide gas, without ever becoming a liquid. This is why you might see “smoke” or “fog” coming off of dry ice – it’s actually carbon dioxide gas.

Another example of sublimation is mothballs. Mothballs are solid balls of a chemical compound called naphthalene, which sublimes at room temperature. Over time, the mothballs will slowly shrink as naphthalene molecules sublimate into the air.

So, in summary, sublimation is a important physical change because it involves a change in the physical state of matter without any change in its chemical composition. It’s a pretty cool phenomenon, and it can be seen in a variety of everyday substances!