Pure Substances and Mixtures

Front

What is a chemical change?

Back

The formation of a new substance with different properties; cannot be undone by physical means.

Front

What is an element?

Back

A pure substance that cannot be broken down chemically into simpler substances.

Front

What is a physical change?

Back

A change which alters the physical properties of a substance without changing its identity.

Front

What do two or more physically combined substances form?

Back

A mixture.

Front

What is sodium chloride (NaCl) classified as?

Back

A compound.

Front

What is a mixture?

Back

A combination of two or more substances that are not chemically bonded.

Front

What is a compound?

Back

A pure substance made by chemically combining two or more elements; represented by a chemical formula.

Front

What is the difference between a pure substance and a mixture?

Back

A pure substance has a uniform and definite composition, while a mixture contains two or more substances that retain their individual properties.

Front

Can a physical change be reversed?

Back

Yes, physical changes can often be reversed.

Front

What is an example of a chemical change?

Back

Burning wood, which produces ash and smoke.