What Burns? What Melts?

Front

What is thermal energy?

Back

Thermal energy is the energy that comes from the temperature of matter. It is the total kinetic energy of the particles in an object.

Front

What happens to a substance when it absorbs thermal energy?

Back

When a substance absorbs thermal energy, it can undergo a phase change, such as melting, boiling, or evaporating.

Front

What is melting point?

Back

The melting point is the temperature at which a solid becomes a liquid.

Front

What is the difference between melting and burning?

Back

Melting is a physical change where a solid turns into a liquid, while burning is a chemical change that produces heat and light, resulting in new substances.

Front

What happens to chocolate when it melts?

Back

When chocolate melts, it changes from a solid to a liquid state due to the absorption of thermal energy.

Front

What is a flash point?

Back

The flash point is the lowest temperature at which a substance can vaporize to form an ignitable mixture in air.

Front

Why does wood burn instead of melt?

Back

Wood burns because its flash point is lower than its melting point, causing it to ignite and undergo combustion.

Front

What phase change occurs when chocolate absorbs enough heat?

Back

The phase change that occurs is from solid to liquid.

Front

At what temperature does wood begin to break down and react with oxygen?

Back

Wood begins to break down and react with oxygen at about 150 °C (302 °F).

Front

What is combustion?

Back

Combustion is a chemical reaction that occurs when a substance reacts rapidly with oxygen, producing heat and light.