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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 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 chemically bond together. For example, water (H2O) is a compound 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 air, salad, and sand and salt.

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What is the difference between an element and a compound?

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An element is a single type of atom, while a compound consists of two or more different types of atoms chemically bonded together.

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Can mixtures be separated?

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Yes, mixtures can be separated by physical means, such as filtration, evaporation, or using a magnet.

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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, such as saltwater or air.

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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, such as a salad or a mixture of sand and pebbles.

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What is the law of conservation of mass?

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The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; it is conserved.

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What is a chemical change?

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A chemical change is a process where substances combine or break apart to form new substances, such as rusting iron or burning wood.

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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, such as melting ice.