Physical and Chemical Changes

Front

What is a chemical change?

Back

A chemical change is a process where one or more substances are transformed into different substances with new chemical properties, often involving a reaction that changes the molecular structure.

Front

What is a physical change?

Back

A physical change is a process that alters the form or appearance of a substance without changing its chemical composition. Examples include changes in state, shape, or size.

Front

Give an example of a chemical change.

Back

An example of a chemical change is burning a candle, where the wax reacts with oxygen to produce heat, light, carbon dioxide, and water.

Front

Give an example of a physical change.

Back

An example of a physical change is ripping up paper, where the paper's physical form is altered but its chemical composition remains the same.

Front

What happens when two clear liquids are mixed and form a blue liquid?

Back

This is an example of a chemical change, as a new substance with different properties is formed.

Front

What is the significance of digestion in terms of chemical change?

Back

Digestion is a chemical change because it involves breaking down food into simpler substances that can be absorbed by the body, altering the chemical structure of the food.

Front

What is melting in terms of physical and chemical changes?

Back

Melting is a physical change where a solid turns into a liquid without changing its chemical composition, such as melting a chocolate bar.

Front

What are indicators of a chemical change?

Back

Indicators of a chemical change include color change, temperature change, gas production, and the formation of a precipitate.

Front

What are indicators of a physical change?

Back

Indicators of a physical change include changes in state (solid, liquid, gas), shape, size, and texture without altering the substance's chemical identity.

Front

How can you differentiate between a physical and a chemical change?

Back

You can differentiate them by observing whether the substance's chemical identity changes (chemical change) or if it only changes in form or appearance (physical change).