Vacuum, used in thermos bottles and instant noodles, is indispensable in our daily lives.
A ‘vacuum’ is a state in which the air is thin and there are n molecules drifting in the air. This article provides an easy-to-understand explanation of the characteristics of such ‘vacuum’.
Contents
Oxidation resistant
There are fewer oxygen molecules in the air, making it less susceptible to oxidation.
There is also less airborne bacteria.
Things such as vacuum-packed bacon and ham can retain their freshness for a long time, due to their resistance to oxidization.
Metal is less likely to rust.
Difficult to lose heat
Heat has the property of being transferred from warm to cold objects.
In a vacuum, there are fewer molecules to transfer that heat, so less heat is lost.
Vacuum flasks make use of this feature of the vacuum.
For more information about how vacuums and vacuum flasks work.
Boiling point falls.
The weight of molecules drifting in the air is called atmospheric pressure, and in a vacuum there are fewer molecules drifting in the air, so the atmospheric pressure is also lower.
Low atmospheric pressure lowers the boiling point.
The boiling point is the temperature at which a liquid becomes a gas.
For example, it is the temperature at which water (liquid) turns into hot water and steam (gas) starts to be produced.
In a vacuum, the boiling point can be at or below the freezing point, and this feature is utilized in instant noodles and other freeze-drying products.
For more information about vacuums and instant noodles, click here.
You can’t hear a sound.
Sound is transmitted by the shaking of air (movement of molecules in the air).
If you listen to a performance in an orchestra hall, for example, holding a thin pamphlet or other paper in both hands, you can feel the air vibrating.
In a vacuum, there are fewer molecules in the air, so sound is less likely to be transmitted.
In cartoons and other films, there are scenes of explosions in space, but there shouldn’t be any sound in real life.
A vacuum has these characteristics because there are fewer molecules in the air.
We offer a variety of vacuum equipment such as sputtering equipment.
