The needle floats because the surface tension of water creates a force that counteracts the weight of the needle.

Adding more soap decreases the surface tension because soap molecules disrupt the cohesive forces between water molecules.

Force = Surface Tension × Length = 0.072 N/m × 0.5 m = 0.036 N.

The spherical shape of a liquid drop minimizes the surface area, which is a result of surface tension acting to reduce the energy of the surface.

The phenomenon of a liquid rising in a narrow tube is called capillarity.

Capillary action occurs due to the combination of surface tension (which pulls the liquid up) and adhesion (which attracts the liquid to the walls of the tube).

The phenomenon of liquid rising in a narrow tube is called capillarity.

A soap bubble adopts a spherical shape because it minimizes the surface area for a given volume, which is energetically favorable due to surface tension.

The capillary rise method is commonly used to measure surface tension by observing the height to which a liquid rises in a capillary tube.

Surfactants lower the surface tension of liquids by disrupting cohesive forces between molecules.

The surface tension of water decreases as temperature increases.

Adding soap decreases the surface tension of water because soap molecules disrupt the cohesive forces between water molecules.

Adding a surfactant decreases the surface tension of water by disrupting the cohesive forces between water molecules.

Adding soap to water decreases its surface tension because soap molecules disrupt the cohesive forces between water molecules.

The surface tension of water decreases with an increase in temperature.

Surfactants decrease the surface tension of water.

As temperature increases, the kinetic energy of the molecules increases, leading to a decrease in cohesive forces and thus a decrease in surface tension.

Surface tension decreases with an increase in temperature due to increased molecular motion.

The formation of droplets is primarily due to surface tension, which minimizes the surface area of the liquid.

Capillarity is primarily caused by surface tension, which allows liquids to rise or fall in narrow spaces against gravity.

Surface tension is inversely proportional to temperature for most liquids.

Due to surface tension, liquid droplets tend to minimize their surface area, resulting in a spherical shape.

A liquid droplet takes a spherical shape because a sphere has the minimum surface area for a given volume, minimizing the energy associated with surface tension.

The unit of surface tension is Newton per meter (N/m).

Surface tension is defined as force per unit length, hence its unit is Newton per meter (N/m).

Adding a surfactant to water decreases the surface tension by disrupting the cohesive forces between water molecules.

Density does not directly affect surface tension; it is influenced by temperature, impurities, and the nature of the liquid.

While temperature, impurities, and the nature of the liquid affect surface tension, density does not directly influence it.

Mercury has a very high surface tension due to strong cohesive forces between its molecules, higher than that of water, ethanol, and benzene.

Floating of heavy objects is not a consequence of surface tension; it is due to buoyancy, while the other options are directly related to surface tension.