How a microwave heats up food.

If you want to heat up food, there are three ways to do it.

Conductive Heat: When you heat up a pan on a stove and then put a piece of chicken on it. The part of the chicken that touches the pan gets very hot very quickly.

Convective Heat: When you heat up an oven and put a turkey inside. The hot air in the oven heats up the turkey.

Radiative Heat: Leaving a glass of cold water in the sun for a long time and when you come back later, it is very warm. The sunlight is shining through the glass and causing the water to heat up.

Cooking in a microwave is similar to radiative heat. But instead of the sun, there are artificial micro "waves". The waves in the microwave are more powerful than the sunlight so when it goes through the food, it bumps into big molecules, mostly water molecules, and heats them up.