Question 1

Define latent heat of fusion.

Accepted Answer

The latent heat of fusion is defined as the amount of heat energy required to change 1 kilogram of a solid into a liquid at its melting point under standard atmospheric pressure without any rise in temperature. This hidden heat energy is absorbed by the solid particles to overcome the strong forces

Question 2

Why does ice float on water despite being a solid?

Accepted Answer

Ice floats on water because it has a cage-like structure formed by hydrogen bonding, which creates empty spaces between its molecules. Due to these vacant spaces, the volume of ice increases, making its density lower than that of liquid water. Objects with lower density than the liquid they are plac

Question 3

Why does a desert cooler cool better on a hot, dry day?

Accepted Answer

A desert cooler cools better on a hot, dry day because the rate of evaporation depends directly on temperature and humidity. On a hot dry day, the temperature is high and the humidity (moisture in the air) is low. High temperature and low humidity both increase the rate of evaporation of water, lead

Question 4

Define sublimation and give two examples of substances that undergo sublimation.

Accepted Answer

Sublimation is the phase transition of a substance directly from the solid state to the gaseous state without passing through the intermediate liquid state upon heating. Similarly, the reverse process is called deposition. Two common examples of sublime substances are ammonium chloride ($NH4Cl$), ca

Question 5

Define diffusion and explain how temperature affects the rate of diffusion.

Accepted Answer

Diffusion is the process of intermixing of particles of two different types of matter on their own. The rate of diffusion increases with an increase in temperature. This happens because increasing the temperature increases the kinetic energy of the particles, causing them to move much faster and int

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