Why do water drops bounce on hot surfaces?

Thread starter Edi
Start date Jul 9, 2009
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In summary, a water drop on a hot surface will quickly evaporate and spread out due to the high temperature and decreased surface tension. Factors such as surface temperature, drop size, humidity, type of surface, and impurities can affect its behavior. This evaporation occurs because the surface temperature is higher than the boiling point of water. While a water drop may be able to remain stable on a moderately hot and humid surface, it will not be as stable as on a cold surface with higher surface tension.

Jul 9, 2009

Edi

There are situations when a water drop falls on a really hot metal surface and, instead of evaporating, it kinda bounces on the surface. Why?

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Jul 9, 2009

Andy Resnick

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Google "Leidenfrost effect"

Jul 9, 2009

Edi

Exelent! Thank you. So simple. :)

Related to Why do water drops bounce on hot surfaces?

1. How does a water drop behave on a hot surface?

A water drop on a hot surface will typically evaporate quickly due to the high temperature of the surface. The surface tension of the water drop will also decrease, causing it to spread out and flatten.

2. What factors affect the behavior of a water drop on a hot surface?

The temperature of the surface, the size of the water drop, and the humidity of the surrounding air can all affect the behavior of a water drop on a hot surface. Additionally, the type of surface and the presence of impurities in the water can also play a role.

3. Why does a water drop evaporate on a hot surface?

When a water drop is placed on a hot surface, the temperature of the surface is higher than the boiling point of water. This causes the water molecules to gain enough energy to break free from the liquid phase and become a gas, leading to evaporation.

4. Can a water drop remain stable on a hot surface?

In most cases, a water drop will not remain stable on a hot surface. However, if the surface is not significantly hotter than the boiling point of water and the humidity is high, a water drop may be able to remain stable for a longer period of time due to slower evaporation.

5. How does the behavior of a water drop on a hot surface differ from that on a cold surface?

A water drop on a cold surface will typically have a higher surface tension and will not spread out or evaporate as quickly. This is because the lower temperature of the surface does not provide enough energy for the water molecules to break free and evaporate.