Unit 2A/3A Test review

Front

What type of change is burning wood?

Back

Chemical change.

Front

What is the chemical formula for three hydrogen (H), one sulfur (S), and four oxygen (O)?

Back

H₃SO₄

Front

What type of change is the melting of wax?

Back

Physical change.

Front

What happens to water particles when energy is added?

Back

They speed up.

Front

What does the small number in a chemical formula represent?

Back

The number of atoms of that element in the molecule.

Front

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

Back

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

Front

Give an example of a chemical change.

Back

Rusting of iron.

Front

Give an example of a physical change.

Back

Dissolving sugar in water.

Front

What is the significance of the coefficients in a chemical equation?

Back

They indicate the number of molecules or moles of each reactant and product.

Front

What is the law of conservation of mass?

Back

Mass is neither created nor destroyed in a chemical reaction.