Chemical and Physical Changes

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and includes processes like burning, rusting, and digestion.

Front

What happens when ice melts?

Back

When ice melts, it undergoes a physical change from solid to liquid without changing its chemical structure.

Front

What happens when a hot glue stick melts?

Back

When a hot glue stick melts, it undergoes a physical change, changing from solid to liquid.

Front

What is an example of a chemical change in the human body?

Back

An example of a chemical change in the human body is the breakdown of food by stomach acid and enzymes.

Front

What occurs when salt is added to water?

Back

When salt is added to water, it dissolves, which is a physical change as the salt retains its chemical identity.

Front

What is photosynthesis?

Back

Photosynthesis is a chemical change where plants convert carbon dioxide and water into glucose and oxygen using sunlight.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change does not alter the chemical composition of a substance, while a chemical change results in new substances being formed.

Front

Can a physical change be reversed?

Back

Many physical changes can be reversed, such as freezing and melting, but not all (e.g., breaking an egg).

Front

Can a chemical change be reversed?

Back

Chemical changes are often not reversible by simple physical means, as they involve the formation of new substances.