Understanding surface tension is important because it helps us figure out how liquids move in narrow spaces. This is called capillary action, and it's useful in many science topics.

1. What is Surface Tension?

   • Surface tension ($\sigma$) is like a stretchy skin on the surface of a liquid. It measures how strong this "skin" is.

2. How Does It Work?

   • The height ($h$) that a liquid rises in a tiny tube can be explained by this formula: $h = \frac{2\sigma \cos(\theta)}{\rho g r}$ Here’s what each part means:
   • $\sigma$ = surface tension (N/m)
   • $\theta$ = contact angle (degrees)
   • $\rho$ = density of the liquid (kg/m³)
   • $g$ = gravity (9.81 m/s²)
   • $r$ = radius of the tube (m)

3. Why Does It Matter?

   • For example, water has a surface tension of about 0.0728 N/m.

Knowing about surface tension helps us understand how liquids act in tiny spaces. This is really important in areas like biology and material science.