If you forget to remove water from a microwave after heating it, several things can occur depending on the circumstances:
Boiling Over: When water is heated in a microwave, it can reach a temperature higher than its boiling point without actually boiling. This is known as "superheating." Superheated water can become unstable, and even a slight disturbance or movement can trigger a rapid boiling overreaction. This sudden release of energy can cause the water to violently boil and splash out of the container, potentially leading to burns or other injuries. It is crucial to handle hot containers with care to avoid such accidents.
Delayed Boiling: In some cases, water may not appear to be boiling, even though it has reached its boiling point. This phenomenon is called "delayed boiling" or "bump boiling." If the water is heated beyond its boiling point but does not encounter any nucleation sites (such as impurities or a rough surface), it can remain in a superheated state. However, when the superheated water is disturbed or a nucleation site is introduced (for example, by dropping something into the water), rapid boiling can occur suddenly and forcefully.
Evaporation: If the water is heated for an extended period, it can eventually evaporate entirely, leaving the container empty. Microwaving water for an excessive amount of time can cause it to evaporate rapidly, potentially leading to overheating and damage to the microwave oven itself.
It is important to exercise caution and follow proper microwave safety practices to prevent accidents. To avoid potential risks, always use microwave-safe containers, handle hot containers carefully, and never heat water for extended periods without supervision.