Why don't the air atoms in the microwave warm up?

In summary, the object you place in the microwave warms up due to electromagnetic waves while the atoms of the air in the microwave also warm up, but at a lower rate. This is because the microwaves couple to rotational modes of water, which has an electric dipole moment, while even diatomic gases in air do not. Despite this, the air does warm up due to the moisture and vapor created from cooking food, but the fans in microwave ovens help to draw out this air.
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Lisastronomy
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TL;DR Summary
The object you place in the microwave warm up because of the electromagnetic waves. How come the atoms of the air of the microwave do not warm up?
The object you place in the microwave warm up because of the electromagnetic waves. How come the atoms of the air of the microwave do not warm up? Or do they only feel like they haven't warmed up, or do they not absorb the energy as much as the object you place in the microwave?
 
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Microwaves at 2.4 GHz couple to rotational modes of water because it has an electric dipole moment. Even the diatomic gases in air do not.
 
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Why don't the air atoms in the microwave warm up?

They do. The microwaves warm the food and the food warms the air.
 
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  • #4
Lisastronomy said:
Summary:: The object you place in the microwave warm up because of the electromagnetic waves. How come the atoms of the air of the microwave do not warm up?

The object you place in the microwave warm up because of the electromagnetic waves. How come the atoms of the air of the microwave do not warm up? Or do they only feel like they haven't warmed up, or do they not absorb the energy as much as the object you place in the microwave?

It's the same reason why microwave-safe containers do not get directly heated by the microwave.

Since you didn't ask about that, I'm assuming that you know why already.

Zz.
 
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There is usually humidity in the air, and cooking food usually creates water vapor inside your microwave oven. You would think that there would be hot moisture-laden air inside the compartment.

Don't all microwave oven have fans that draw out the air from the cooking compartment during the cooking process?
 
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FAQ: Why don't the air atoms in the microwave warm up?

1. Why don't the air atoms in the microwave warm up?

The air atoms in a microwave do not warm up because they are not directly affected by the microwave's radiation. The microwave's energy is primarily absorbed by water molecules, which causes them to vibrate and generate heat. Air molecules do not have the same molecular structure as water and therefore do not respond to the microwave's energy in the same way.

2. Why does food heat up in a microwave but not the air inside?

As mentioned, the microwave's energy is primarily absorbed by water molecules, which are present in most foods. The water molecules vibrate and generate heat, which then transfers to the food. However, air molecules do not have the same molecular structure as water and therefore do not absorb the microwave's energy in the same way, resulting in them not heating up.

3. Can the air in a microwave ever get hot?

In some cases, the air inside a microwave may feel warm after heating food because the food itself heats up the air around it. However, this is not due to the microwave's radiation directly heating the air molecules. The warm air is a result of the heat transfer from the heated food to the surrounding air.

4. Is it safe to put a cup of water in the microwave without anything else?

Yes, it is safe to put a cup of water in the microwave without anything else. Water molecules readily absorb the microwave's energy and generate heat, so the cup of water will heat up. However, it is important to use caution when handling the hot water after heating it in the microwave.

5. Why does the air inside a microwave feel warm after using it?

After using a microwave, the air inside may feel warm due to the heat transfer from the heated food to the surrounding air. However, this is not the same as the air molecules themselves being heated by the microwave's radiation. The heat is a result of the heated food, not the microwave's energy directly affecting the air molecules.

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