Elements, Compounds, Mixtures, & Counting atoms

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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 are chemically bonded together. Examples include water (H2O) and carbon dioxide (CO2).

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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 (a mixture of gases) and salad (a mixture of vegetables).

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What is the difference between a pure substance and a mixture?

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A pure substance has a uniform and definite composition, while a mixture contains two or more substances that retain their individual properties.

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How do you identify a mixture of elements?

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A mixture of elements can be identified by the presence of two or more different types of atoms that are not chemically bonded together.

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What does the formula C2H8O represent?

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The formula C2H8O represents a compound made up of 2 carbon (C) atoms, 8 hydrogen (H) atoms, and 1 oxygen (O) atom.

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How many total atoms are in the compound C2H8O?

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There are 11 total atoms in the compound C2H8O (2 C + 8 H + 1 O = 11).

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What is the chemical formula for potassium chloride?

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The chemical formula for potassium chloride is KCl.

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What does KCl2 represent?

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KCl2 represents a compound made up of potassium (K) and chlorine (Cl) atoms, specifically two chlorine atoms for each potassium atom.

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What is a pure substance that is an element?

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A pure substance that is an element consists of only one type of atom. Examples include helium (He) and iron (Fe).