Outcome 5: energy and phase changes

Front

What happens to energy when a substance cools down?

Back

The substance loses energy.

Front

What are the points on a phase change diagram where a substance changes phase?

Back

The points where phase changes occur are indicated by segments such as B-C and D-E.

Front

Which line segment on a phase change diagram represents the solid state?

Back

The line segment A-B represents only the solid state.

Front

What does it indicate if a substance's temperature decreases but its phase remains the same?

Back

It indicates that the substance is cooling down without changing its phase.

Front

What is a phase change?

Back

A phase change is a transition of a substance from one state of matter to another, such as solid to liquid or liquid to gas.

Front

What is the significance of the flat regions on a phase change diagram?

Back

The flat regions indicate phase changes where temperature remains constant while energy is added or removed.

Front

What is the relationship between temperature and energy during a phase change?

Back

During a phase change, the temperature remains constant while energy is either absorbed or released.

Front

What does it mean if a substance is in the liquid state on a phase change diagram?

Back

It means that the substance has enough energy to overcome some intermolecular forces but not enough to completely break free into the gas state.

Front

How can you identify the solid state on a phase change diagram?

Back

The solid state can be identified in the regions where the temperature is low and the substance is not changing phase.

Front

What occurs during the melting process?

Back

During melting, a solid absorbs energy and transitions into a liquid.