Why Does an Egg float in Salt water?
When we look at the weights of two objects like copper metal and thermocole, the former will have more weight than that of the latter of same size. So it is obvious that the heavy object will sink into water while the lighter object floats on water. It is easy to determine the relative densities of some materials or substances. There is another way of finding out the densities of two substances. When an object is put on the waters, if its density is more than the density of the water that it has displaced the water, so it will sink. If its density is less than the same amount of liquid or water, then it will float. Density is weight per unit volume of the object. The densities of solids remain constant while that of liquids and gases change with a change in temperature.
The density of the water or liquid also changes if any substance is dissolved in it. For instance, when salt is added to water the density of it increases. When any object slightly denser than the freshwater is put into salt water, it will have enough salt to make the water denser than the object. That object will then float in salt water.
It is found that egg is of the same density as that of normal water. This means that both of them weigh the same per unit volume. When salt is added to water, some more mass is added into it without any change in the volume. The weight of unit volume of normal water will be less than that of salt water based on the quantity of salt that was added. However, the density of egg remains the same even though that of water changes. As the density of salt water now is more than the density of the egg, egg floats in salt water. Not only salt, but anything that dissolves in water like sugar will also show a similar phenomenon.