3. Compounds and molecules

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What is a mixture?

Back

A mixture is a combination of two or more substances that are not chemically bonded together. Examples include air, salad, and saltwater.

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What is a compound?

Back

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

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What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Examples include hydrogen (H), oxygen (O), and carbon (C).

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Can elements be broken down into simpler substances?

Back

No, elements cannot be broken down into simpler substances.

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What is the difference between a mixture and a compound?

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A mixture consists of two or more substances that are not chemically combined, while a compound consists of two or more elements that are chemically bonded.

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What is an example of a mixture of different elements?

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Air is an example of a mixture of different elements, including nitrogen (N), oxygen (O), and carbon dioxide (CO2).

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What does the term 'chemical bond' refer to?

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A chemical bond is the force that holds atoms together in a compound. There are different types of chemical bonds, including ionic and covalent bonds.

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What is a homogeneous mixture?

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A homogeneous mixture is a mixture that has a uniform composition throughout. An example is saltwater.

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What is a heterogeneous mixture?

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A heterogeneous mixture is a mixture that does not have a uniform composition and the different components can be seen. An example is a salad.

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What is a molecular compound?

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A molecular compound is a compound formed by the sharing of electrons between nonmetal atoms. An example is carbon dioxide (CO2).