Atoms & Mixtures

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus containing protons and neutrons, surrounded by electrons.

Front

What is a mixture?

Back

A mixture is a combination of two or more substances where each substance retains its own properties. Mixtures can be homogeneous or heterogeneous.

Front

Define homogeneous mixture.

Back

A homogeneous mixture is a mixture in which the composition is uniform throughout. Examples include saltwater and air.

Front

Define heterogeneous mixture.

Back

A heterogeneous mixture is a mixture in which the composition is not uniform throughout. Examples include salad and cereal with milk.

Front

What is a pure substance?

Back

A pure substance is a material that has a constant composition and consistent properties throughout. Examples include elements and compounds.

Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically bond together in a fixed ratio. Examples include water (H2O) and carbon dioxide (CO2).

Front

What is an element?

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An element is a pure substance that cannot be broken down into simpler substances by chemical means. Examples include gold (Au) and oxygen (O2).

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What is the difference between a compound and a mixture?

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A compound is a chemical combination of two or more elements, while a mixture is a physical combination of two or more substances that retain their individual properties.

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What is an example of a pure substance?

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Gold is an example of a pure substance because it consists of only one type of atom.

Front

What does the term 'molecule' refer to?

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A molecule is a group of two or more atoms bonded together. Molecules can be made of the same or different elements.