Question

State true or false:
Ice is less dense than water ( because it has more volume for the same mass,) which is why ice floats on water.
A. True
B. False

Answer 1

Hint: To begin with, clearly both water and ice are made of the same type of molecules namely the water molecules. However, they differ from each other in the state of matter or the type force acting between them.

Complete answer:
We know that density of a substance is the ratio of the mass to the volume of the substance. Clearly, both mass and volume both affect the density of the substance.
We know that when an object is immersed in a liquid, it experiences an upward thrust or force called the buoyant force. This property or nature of liquids is called buoyancy. This is caused due to the difference in the pressure above and inside liquid. Similarly, Archimedes principle, we know that the buoyant force is equal to the weight of the fluid displaced.

Archimedes principle and buoyancy are two important properties which are often used in fluid mechanics. Buoyancy has wide applications like the designing of submarines, aeroplanes. It is also used by birds and fish to move through the water and air respectively
Then, we can say that the mass of the substance is the deciding factor, if the substance floats or sinks.
Also, we know Water has a density of and the density of ice is. If we assume that the volume remains the same, we can clearly see that the
The mass of ice is smaller as compared to that of the liquid water.
Hence we can conclude that Ice is less dense than water and hence ice floats on water.

So, the correct answer is “Option A”.

Note:
Mass is a property of the substance, whereas weight is the force due to gravity acting on the body with some mass. Also, Archimedes principle and buoyancy are properties of liquids and can be extended to fluids as well.