Explain why soap bubbles burst after a certain time?

In short (click here for detailed version)

Soap bubbles burst after a certain time because the liquid they are made of evaporates gradually. When the liquid layer becomes too thin, it can no longer retain the air pressure inside the bubble, causing it to burst.

Explain why soap bubbles burst after a certain time?
In detail, for those interested!

First cause: evaporation of the liquid.

When a soap bubble is blown, it contains a mixture of soap liquid and trapped air inside. The main reason why a soap bubble bursts is due to the evaporation of the liquid. In fact, as soon as the bubble is formed, the soap liquid on the surface of the bubble begins to evaporate into the surrounding air. This evaporation leads to a decrease in the amount of liquid on the surface of the bubble, weakening its structure and eventually leading to its rupture. The rate of evaporation depends on factors such as temperature, air humidity, and the chemical composition of the soap liquid. The higher the temperature and the lower the humidity, the faster the evaporation will be, which may explain why soap bubbles tend to burst more quickly in hot and dry weather. The gradual decrease of soap liquid on the surface of the bubble weakens the structure of the bubble, which can lead to air leaks and the bursting of the bubble.

Second cause: surface tension

Surface tension is a force that acts at the surface of a liquid and tends to minimize the exposed surface. This force is due to interactions between the molecules of the liquid. When a soap bubble forms, the surface tension force acts to reduce the surface of the bubble to the minimum possible. This allows the bubble to take on a spherical shape, as a sphere offers the smallest surface area for a given volume.

However, over time, surface tension can be altered by factors such as temperature, water quality, or the composition of the liquid inside the bubble. When surface tension is disrupted, the shape of the bubble can become unstable. The molecules at the surface of the bubble are then less strongly attracted to each other, which can lead to distortions in the shape of the bubble.

As a result, as surface tension decreases, the soap bubble becomes more and more fragile. The walls of the bubble become thinner and more vulnerable. Eventually, the bubble reaches a point where it is no longer able to contain the liquid inside and bursts. This process is an example of how surface tension influences the lifespan of a soap bubble.

Third cause: contact with rough surfaces.

When soap bubbles come into contact with rough surfaces, they tend to burst more quickly. Indeed, the roughness of the surfaces causes micro-breaks in the thin layer of soap that makes up the bubble. These micro-breaks cause a decrease in the thickness of the bubble wall, making it more fragile and more prone to bursting. The irregularities on the rough surface create points of concentration of mechanical stresses, further weakening the bubble wall and leading to a decrease in its lifespan. As a result, soap bubbles are more likely to burst when they come into contact with rough surfaces, which can be observed in various everyday situations.

Did you know?

Good to know

Frequently Asked Questions (FAQ)

1

What is the role of soap in the formation of bubbles?

Soap reduces the surface tension of water, allowing the formation of soap bubbles.

2

Why do soap bubbles have colors?

The colors of soap bubbles are due to light interference reflecting on both the front and back surfaces of the bubble.

3

How does the ambient temperature affect the lifespan of soap bubbles?

A high temperature promotes faster evaporation of the liquid, which leads to a shorter lifespan of the bubbles.

4

Is it possible to extend the lifespan of a soap bubble?

Yes, making sure to maintain a low-wind environment and avoiding contact with rough surfaces.

5

What are the dangers of ingesting soap bubbles?

Commercial soap bubbles can contain potentially harmful chemicals if ingested.

Natural Sciences : Chemistry

0% of respondents passed this quiz completely!

Quizz

Question 1/4