Dry ice skips the liquid stage entirely and turns straight from a solid into a gas.

The longer version

Solid carbon dioxide sits at a pressure and temperature where the liquid form is not stable. Instead of melting, its molecules escape directly from the frozen block into the air, a jump scientists call sublimation. The white fog seen around it is not the gas itself, which is invisible, but water droplets condensed from chilled surrounding air.

The same jump happens with ordinary ice on a dry, windy day, when snow seems to vanish without wetting the ground. The difference is one of degree: for carbon dioxide the liquid state only exists above a certain pressure, roughly five times normal atmospheric pressure, so at everyday pressures it is simply skipped.

Where this entry sits

Everyday physics and chemistry hide small wonders in plain sight, from kitchen reactions to the light in the sky. These short facts explain matter, energy, electricity, magnets, sound, and the simple units we use to measure the world. The full list sits on the Science and Physics page, where every entry is listed in order.