The reason why you can put aluminum foil and other metals in the oven but not in the microwave is due to the way microwaves and ovens heat food.
Microwaves work by emitting electromagnetic waves at a frequency that excites water, fats, and sugars molecules in the food. When these molecules absorb the microwave energy, they vibrate and generate heat, which cooks the food. However, metals reflect microwaves rather than absorbing them, which can cause electrical currents to build up. This can result in a phenomenon called arcing, where sparks can occur and potentially damage the microwave or create a fire hazard.
On the other hand, conventional ovens use heating elements or gas burners to generate heat. They heat the air inside the oven, and this hot air then transfers heat to the food. Metals, including aluminum foil, are generally safe to use in ovens because they do not cause arcing. Instead, they help distribute heat more evenly by reflecting and conducting it.
It's important to note that while aluminum foil is generally safe to use in ovens, you should avoid using it in direct contact with acidic or salty foods, as these can cause a reaction that may damage the foil and affect the taste of the food.
In summary, microwaves and ovens operate differently when it comes to heating food. Microwaves rely on the absorption of microwave energy by water molecules, while ovens use conventional heating methods. Metals, including aluminum foil, can cause arcing in microwaves but are generally safe to use in ovens due to their reflective and conductive properties.