Balancing Chemical Equations

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Chemical Equation Noun

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[kem-i-kuhl ee-kway-zhun]

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Chemical Equation

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A symbolic representation of a chemical reaction showing the reactants on the left and the products on the right side.

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Example: This image shows a chemical equation where reactant molecules (methane and oxygen) rearrange their atoms to form new product molecules (carbon dioxide and water).

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Reactant Noun

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[ree-ak-tunt]

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Reactant

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A substance that participates in and undergoes change during a chemical reaction, found on the left side of an equation.

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Example: This diagram shows that reactants, like Methane and Oxygen, are the starting substances on the left side of the arrow in a chemical reaction.

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Product Noun

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[prod-ukt]

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Product

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A substance that is formed as the result of a chemical reaction, found on the right side of an equation.

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Example: The products, two water molecules (2H₂O), are the new substances formed on the right side of the arrow during this chemical reaction.

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Law of Conservation of Mass Noun

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[law uv kon-ser-vay-shun uv mas]

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Law of Conservation of Mass

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The fundamental principle stating that mass in an isolated system is neither created nor destroyed by chemical reactions.

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Example: In a closed flask, the total mass of the chemicals remains the same before and after they react, demonstrating that mass is conserved.

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Coefficient Noun

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[koh-uh-fish-unt]

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Coefficient

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A number placed before a chemical formula in an equation that indicates how many molecules are involved in the reaction.

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Example: The coefficient '2' in front of the oxygen (O₂) and water (H₂O) indicates the number of molecules needed to balance the chemical equation.

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Subscript Noun

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[sub-skript]

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Subscript

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A number written slightly below and to the right of a chemical symbol, indicating the number of atoms in a molecule.

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Example: The subscript '2' in the chemical formula CO₂ indicates there are two oxygen atoms bonded to one carbon atom in a single molecule.

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Atom Noun

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[at-um]

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Atom

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The smallest unit of ordinary matter that forms a chemical element and retains the properties of that specific element.

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Example: This diagram shows an atom has a central nucleus of protons and neutrons, with electrons orbiting in shells, defining it as a basic unit of matter.

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Molecule Noun

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[mol-i-kyool]

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Molecule

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An electrically neutral group of two or more atoms held together by chemical bonds, forming the smallest unit of a compound.

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Example: This image shows a single water molecule, which is made of two hydrogen (H) atoms and one oxygen (O) atom chemically bonded together.

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Balanced Equation Noun

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[bal-unssd ee-kway-zhun]

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Balanced Equation

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A chemical equation in which the number of atoms for each element in the reaction is equal on both sides.

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Example: This balanced scale represents a balanced chemical equation, where the mass of the reactants on one side equals the mass of the products on the other.

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Chemical Reaction Noun

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[kem-i-kuhl ree-ak-shun]

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Chemical Reaction

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A process that leads to the chemical transformation of one set of chemical substances into another set of substances.

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Example: This image shows four common signs that a chemical reaction has occurred: gas formation, energy change, color change, and precipitate formation.