Effect of Heat on Change of State of Matter

How does a substance change from solid to liquid?

When a solid substance is heated, its vibrations increase, increasing its temperature. When the substance reaches a certain temperature, the vibrations of its molecules become so great that the molecules begin to move away from each other, and the substance changes from a solid state to a liquid state.

What are melting and melting point?

The process of changing from a solid to a liquid state is called melting. The temperature at which a solid substance begins to melt is called its melting point. The melting point of a substance at atmospheric pressure is called its normal point. The normal melting point of ice is 0 degrees Celsius (0^oC).

Explain evaporation and boiling point.

The process of changing from a liquid to a gaseous state is called evaporation. The temperature at which a liquid substance begins to change into a gaseous substance is called its boiling point. The boiling point of a substance at atmospheric pressure is called its normal boiling point. The normal boiling point of water is 100 degrees Celsius (100^oC).

How does a substance change from gas to liquid?

If heat is removed from a gaseous substance, the temperature of the gaseous substance decreases, and at a certain temperature, the substance changes into a liquid substance. The process of changing from a gaseous state to a liquid state is called condensation. The condensation. The condensation of water vapor in the air into dew is an example of condensation.

How does a solid substance change into a gas?

Some substances, when heated, do not transform into liquids first but directly into gaseous substances. The process by which a solid substance is heated and directly converted into vapor without passing through the liquid state is called sublimation. Naphthalene, a solid moth repellent used in clothes, directly turns into vapor when heated without becoming a liquid. This is an example of sublimation.