Early Ideas About Matter

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Matter Noun

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[mat-er]

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Matter

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The substance of which all physical objects are made, possessing mass and occupying space in the universe.

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Example: This diagram shows that matter is made of particles and exists in different states (solid, liquid, gas) based on how those particles are arranged.

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Atom Noun

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[at-uhm]

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Atom

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The smallest unit of ordinary matter that forms a chemical element, consisting of a nucleus and surrounding electrons.

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Example: This diagram shows the structure of an atom, which has a central nucleus containing protons and neutrons, and is surrounded by electrons in shells.

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Homogeneous Adjective

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[hoh-muh-jee-nee-uhs]

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Homogeneous

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Having a uniform structure or composition throughout; consistent and of the same or a similar kind or nature.

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Example: The image shows a solution, a type of homogeneous mixture, where the solute particles are uniformly distributed among the solvent particles at a microscopic level.

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Hypothesis Noun

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[hy-poth-uh-sis]

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Hypothesis

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A proposed explanation for a phenomenon made as a starting point for further investigation through experimentation.

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Example: This icon shows a lightbulb (an idea) with a question mark inside, representing a hypothesis as a testable question or proposed explanation.

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Atomic Theory Noun

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[uh-tom-ik thee-uh-ree]

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Atomic Theory

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A scientific model explaining that all matter is composed of discrete, fundamental units called atoms.

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Example: This diagram shows a model of an atom, which consists of a central nucleus (containing protons and neutrons) orbited by electrons.

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Mass Ratio Noun

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[mas rey-shee-oh]

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Mass Ratio

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The proportion by mass of the elements that are present within a specific chemical compound.

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Example: This image shows a balance where one large sphere has the same mass as four smaller spheres, illustrating that different quantities of objects can have an equal total mass.

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Compound Noun

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[kom-pound]

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Compound

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A substance formed when two or more different chemical elements are chemically bonded together in fixed proportions.

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Example: This image shows a model of a carbon dioxide (CO₂) molecule, where one carbon atom is chemically bonded to two oxygen atoms, forming a compound.

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Chemical Reaction Noun

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

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Chemical Reaction

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A process that involves the rearrangement of the molecular or ionic structure of a substance, as opposed to a physical change.

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Example: This diagram shows reactants (methane and oxygen) rearranging their atoms to form new products (carbon dioxide and water), demonstrating a chemical reaction.

Front

Law of Conservation of Mass Noun

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[law uv kon-ser-vey-shuhn uv mas]

Back

Law of Conservation of Mass

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The principle stating that for any system closed to all transfers of matter, the mass of the system must remain constant.

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Example: This diagram shows that when two chemicals are mixed in a sealed flask, the total mass on the scale remains the same before and after the chemical reaction.