MCQ Detailed View

When a fresh egg is placed in normal water, it sinks to the bottom because its density is slightly greater than that of pure water. Density is defined as mass per unit volume, and whether an object sinks or floats depends on its density relative to the liquid in which it is placed.

However, when the same egg is placed in salt water, it floats. This is because adding salt to water increases the water’s density. As the concentration of salt rises, the solution becomes denser than the egg. According to the principle of buoyancy, an object will float if it is less dense than the liquid it displaces. Since the salt water is now denser than the egg, the egg is pushed upward and floats on the surface.

This phenomenon is a practical example of Archimedes’ Principle, which states that an object submerged in a fluid experiences an upward force equal to the weight of the fluid it displaces. In fresh water, the displaced water weighs less than the egg, so the egg sinks. In salt water, the displaced salt water weighs more, so the egg rises and floats.

This simple experiment is often used to demonstrate the effect of salinity and density in classrooms. It also relates to natural phenomena: for example, it is easier for humans to float in the Dead Sea because its high salt content makes the water much denser than ordinary seawater.

To summarize:

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  In pure water → the egg sinks.

  
  


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  In salt water → the egg floats.

  
  

Thus, the correct answer is Float, because the density of salt water is higher than that of a fresh egg, allowing buoyancy to lift it to the surface.