How does heating or cooling air affect the air’s volume?

As the air gets warm, molecules start to vibrate and they start to run into each other which makes the space around each of the molecules. Since each molecule takes up more space when it moves, the air gets bigger to let that happen and the air becomes denser or lighter!

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.