Can a microwave oven be used to heat water?

Now that life has become better, many families have bought microwave ovens. When they want to eat, they heat it in the microwave, which is convenient and saves time. Sometimes I go to the supermarket to buy some corn kernels and put them in the microwave to make popcorn. However, there are many taboos when using microwave ovens. For example, iron objects cannot be heated in a microwave oven. So can you heat water in a microwave?

When people use microwave ovens, they not only use them to make coffee, heat milk, heat meals, and toast bread, but also to cook a variety of delicious dishes. So, can microwave ovens also be used to boil water?

Let's look at the principle of boiling water: the kettle boils water directly on the stove. As the water temperature rises, circulation occurs inside the kettle. In addition, some tiny scratches on the kettle wall or tiny overheated particles at the bottom of the kettle, substances called crystal nuclei, cause some water molecules to change from liquid to gas, forming steam bubbles that rise to the surface of the water. Subsequently, a large number of bubbles are formed and continue to rise, which means that the water has reached a constant temperature of 100°C. That is the boiling point of water. When a microwave oven uses a heater such as glass to boil water, the inner surface of the container is very smooth and there is no (or almost no) material that can serve as a crystal nucleus.

In addition, when the microwave oven is working, the container itself does not generate heat and the water does not circulate turbulently. Since there are no crystal nuclei, no bubbles will be generated in the water, and of course no tumbling and boiling phenomenon will be seen, so it is impossible to know whether the water is boiled (that is, the water temperature has reached 100℃). If the heating time is long, the water may become hotter and even exceed the boiling point. At this time, the water is superheated water, but people may not be fully aware of it. When you place a microwave container filled with superheated water on the table, a slight bump will disturb the water inside the container, and the resulting turbulence will act as a kind of crystal nucleus, causing the water to suddenly boil and splash out. Sometimes the disturbance process is much more violent. For example, when you add coffee or tea bags to a container, the superheated water will be significantly impacted, and the large number of water molecules that are eager to vaporize in the water will take advantage of the situation to explode into water vapor molecules.

If the temperature is high enough, water may splash out and cause burns. Therefore, under normal circumstances, it is best not to use a microwave to boil water. If you urgently need boiling water and only a microwave is available, you can let the water sit for a while after it is boiled, or put a spoon (non-metallic, microwave spoon) in the container in advance and let it promote the boiling of water like a crystal nucleus, thus avoiding scalding accidents.

Friends who want to heat water in a microwave must remember the above requirements, otherwise it is easy to cause harm. It is best to have a pair of microwave gloves at home to avoid burns when taking things out of the microwave. Everyone has a certain understanding of the use of microwave ovens, but did you know that the radiation from microwave ovens is very high?