Elements, Compounds, and Mixtures

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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. Examples include water (H2O) and table salt (NaCl).

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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 oxygen (O) and gold (Au).

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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. The components can be separated by physical means. Examples include air and salad.

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What is the difference between a homogeneous mixture and a heterogeneous mixture?

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

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Can compounds be separated into their elements?

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Yes, compounds can be separated into their elements through chemical reactions.

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What is a pure substance?

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A pure substance is a material that has a constant composition and properties throughout. It can be an element or a compound.

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What are some examples of elements?

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Examples of elements include hydrogen (H), carbon (C), and iron (Fe).

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What are some examples of compounds?

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Examples of compounds include carbon dioxide (CO2), sodium chloride (NaCl), and glucose (C6H12O6).

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What is a physical change?

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A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting and boiling.

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What is a chemical change?

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A chemical change is a change that results in the formation of new chemical substances. Examples include rusting of iron and burning wood.