Elements, Compounds, Mixtures PICTURES

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What is the definition of an element?

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An element is a pure substance that cannot be broken down into simpler substances by chemical means. It consists of only one type of atom.

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What is a compound?

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A compound is a substance formed when two or more different elements are chemically bonded together.

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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 and can be separated by physical means.

Front

What distinguishes a homogeneous mixture from a heterogeneous mixture?

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A homogeneous mixture has a uniform composition throughout, while a heterogeneous mixture has a non-uniform composition with distinct phases.

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Can a mixture be classified as a compound? Why or why not?

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No, a mixture cannot be classified as a compound because a mixture consists of two or more substances that are not chemically bonded, whereas a compound is made up of elements that are chemically bonded.

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What is an example of a mixture of elements?

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An example of a mixture of elements is air, which contains various gases like nitrogen, oxygen, and carbon dioxide.

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What is an example of a mixture of compounds?

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An example of a mixture of compounds is saltwater, which contains dissolved sodium chloride (a compound) in water (another compound).

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How can you separate the components of a mixture?

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Components of a mixture can be separated using physical methods such as filtration, distillation, or evaporation.

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What is the significance of the law of definite proportions in compounds?

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The law of definite proportions states that a chemical compound always contains its component elements in fixed ratio by mass, regardless of the sample size or source.

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

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A chemical change results in the formation of new substances with different properties, while a physical change does not alter the chemical composition of a substance.