Plates and cups can break when you put them in the microwave due to a phenomenon known as thermal shock. Thermal shock occurs when there is a rapid and uneven change in temperature, which can cause materials to expand or contract at different rates.
Microwaves heat food by emitting electromagnetic waves that excite the water molecules within the food, generating heat. However, plates and cups are typically made of materials like ceramic, porcelain, or glass, which are not as good at absorbing microwaves as water. As a result, the food absorbs most of the microwave energy, while the plate or cup remains relatively cool.
When you take the plate or cup out of the microwave, the temperature difference between the hot food and the cooler dish can be quite significant. This sudden difference in temperature can create stress within the material, causing it to expand or contract rapidly. If the stress becomes too much for the plate or cup to handle, it can lead to cracks or even complete breakage.
To prevent this from happening, it's important to use microwave-safe dishes and follow the manufacturer's guidelines. Microwave-safe dishes are specifically designed to withstand the rapid temperature changes that occur during microwave heating. They are usually made of materials that can absorb and distribute heat more evenly, reducing the risk of thermal shock.
Additionally, avoid using dishes that have metallic accents, such as gold or silver trim, as they can cause arcing and potentially damage the microwave. It's always a good idea to check the labels or markings on your dishes to ensure they are microwave-safe before using them.