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What is an element?

Back

An element is a pure substance that consists of only one type of atom. Examples include hydrogen (H), oxygen (O), and gold (Au).

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What is a compound?

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A compound is a substance formed when two or more elements are chemically bonded together. An example is water (H2O), which is made of hydrogen and oxygen.

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What is a mixture?

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

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What distinguishes a homogeneous mixture from a heterogeneous mixture?

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A homogeneous mixture has a uniform composition throughout (like saltwater), while a heterogeneous mixture has a non-uniform composition (like a salad).

Front

What is the chemical formula for table salt?

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The chemical formula for table salt is NaCl, which indicates it is a compound made of sodium (Na) and chlorine (Cl).

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Can elements be broken down into simpler substances?

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No, elements cannot be broken down into simpler substances by chemical means.

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

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A physical change alters the form of a substance but not its chemical composition (like melting ice), while a chemical change results in the formation of new substances (like rusting iron).

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What is an example of a compound?

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An example of a compound is carbon dioxide (CO2), which consists of carbon and oxygen.

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What is an example of a heterogeneous mixture?

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An example of a heterogeneous mixture is a bowl of cereal with milk, where the components can be seen and separated.

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What is the process of combining elements to form a compound called?

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The process of combining elements to form a compound is called chemical bonding.