What is required for electricity to flow? explain.

Potential difference between the ends of a circuit. Electrons flow from high potential to low potential

potential diffrencs between the ends of a circuit. electrons flow from high potential to low potential

Explanation:

When we heat a solid substance and if it changes into liquid state then this process is known as melting.

Since, heat is provided to melt the substance therefore, there will be high kinetic energy of molecules. Hence, energy is gained by molecules.

When a solid changes directly into gaseous state without undergoing liquid state then this process is known as sublimation.

For example, naphthalene ball reduces in size when left for long period of time shows sublimation.

Since solid changes into gas therefore, energy is gained in sublimation.

In freezing, molecules come close to each other as molecules come to rest. Thus, there is no gain of energy in freezing.In vaporization, liquid changes into vapour or gaseous state. Therefore, energy is also gained in vapourization.In condensation, vapour or gases change into liquid state. This means there will be decrease in kinetic energy of molecules. Hence, there will be no gain of energy in condensation.In deposition, molecules come to rest at one place. Therefore, there will be no gain of energy in deposition.

Thus, we can conclude that following changes of state are characterized by having atoms that gain energy:

Melting.Sublimation.Vapourization.