Physical and Chemical Change

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 breaking and forming bonds between atoms.

Front

What happens to molecules during a chemical reaction?

Back

During a chemical reaction, bonds between atoms are broken and new bonds are formed, resulting in the creation of new molecules.

Front

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

Back

A physical change does not change the substance's chemical identity, while a chemical change results in the formation of new substances.

Front

What are some signs of a chemical change?

Back

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

Front

What is a precipitate?

Back

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What is the role of energy in chemical reactions?

Back

Energy is either absorbed or released during chemical reactions, which can make the surroundings feel hotter or cooler.

Front

What is an example of a physical change?

Back

An example of a physical change is ice melting into water.

Front

What is an example of a chemical change?

Back

An example of a chemical change is rust forming on iron.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.