Question

What causes a sealed bag of vegetables to expand when it is heated in a

microwave oven?
A. The pressure of the gas changes.
B. The temperature of the gas changes.
C. The size of the molecules changes.
D. The number of molecules changes.

Answer 1

When a sealed bag of vegetables is heated in a microwave oven, the pressure of the gas inside the bag changes, causing it to expand.

Step-by-step explanation:

The correct answer is A. The pressure of the gas changes.

When a sealed bag of vegetables is heated in a microwave oven, the heat causes the water molecules inside the vegetables to vaporize and turn into steam. As the steam cannot escape the sealed bag, it increases the pressure inside the bag, causing it to expand.

This is similar to what happens when you boil water in a closed container, like a kettle. The pressure inside the kettle increases as the water boils and turns into steam, causing the lid to lift or whistle to blow.

Learn more about Microwave oven heating