Liquefaction.
Is ice a solid or a liquid?
Ice is a solid.
When heat is applied to ice, what becomes of the ice?
The ice is changed into water.
Is water a liquid?
Water is a liquid.
How then can a solid be changed to a liquid?
By applying heat to a solid, it may be changed to a liquid.
What is meant by liquefaction?
Liquefaction is the changing of a solid to a liquid, by heat.
How may tallow be melted?
By heating the tallow, it may be melted.
Will the tallow become hard again when cold?
It will be hard again when cold.
Can lead and other metals be melted?
They can be melted or changed to a liquid state by heat.
Can all solids be changed to liquids?
No; there are many solids, such as wood, coal, paper, and leather, that cannot be changed to liquids.
How can a liquid be changed to a solid?
By taking heat away from the liquid, it may be changed to a solid.
Why is a solid melted by heat?
Because heat forces the particles of the solid apart, until it is changed to a liquid.
