Chemistry Vocabulary 1

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condensation point

Back 1

The temperature at which a substance changes from a gas to a liquid at standard atmospheric pressure. Because evaporation (boiling) is the reverse of condensation, the condensation point is numerically equal to the boiling point.

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evaporation

Back 2

A change from the liquid state tot he gaseous state, usually occurring below the boiling point.

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sublimation

Back 3

A change from the solid state directly to the gaseous state.

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states of matter

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The physical states in which matter can occur: solid, liquid, and gas.

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chemical transformation

Back 5

Another term for chemical reaction.

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technology

Back 6

The application of scientific knowledge.

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pure substances

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Only a single type of matter is present.

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freezing

Back 8

The temperature at which a substance changes from a liquid to a solid at standard atmospheric pressure. Because melting is the reverse of freezing, the freezing point is numerically equal to the melting point.

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elements

Back 9

A pure substance composed of atoms of a single element. Compare compound

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chemical reaction

Back 10

A process in which one or more reactants are transformed into one or more products through the breaking of chemical bonds in the reactant molecules and the formation of new chemical bonds in the product molecules.

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product

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A substance produced in the course of a chemical reaction by the transformation of one or more reactants. Compare reactants.

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mixtures

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Occur when two or more pure substances are intermingled with each other.

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reactant

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A starting material for a chemical reaction a substance that enters into the reaction and is transformed into one or more product substances. Compare product.

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scientific method

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The method of making ovservations, proposing theories, and testing those theories through experimentation.

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science

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The experimental investigation and explanation of natural phenomena.

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theory

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A tentative explanation for a set of observations. A theory must be consistent with every one of the observations and is tested through experiments. Compare law.

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experiment

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Procedures that scientists carry out to study some phenomenon.

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law

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A statement that describes the way things are consistently observed to behave under a given set of circumstances. Compare theory.

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bias

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A strong preference or inclination that inhibits impartial judgment.

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chemistry

Back 20

The Study of matter and the transformations it undergoes.

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chemical property

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A property of a substance that can be studied only by having the substance undergo a chemical change; a property that determines the chemical reactions the substance can undergo. Compare physical property.

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melting point (mp)

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The temperature at which a substance changes from a solid to a liquid at standard atmospheric pressure. Because freezing is the reverse of melting, the melting point is numerically equal to the freezing point.

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solution

Back 23

A homogeneous mixture of a solute or solutes dissolved in a solvent.

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homogeneous mixtures

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(homo meaning same) are ones in which the composition of the mixture is identical throughout solution.

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atom

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The smallest unit of an element that has the properties of that element. An atom consists of a central nucleus plus one or more electrons outside the nucleus; the number of electrons is equal to the number of protons, making an atom electrically neutral. Compare ion.

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heterogeneous mixture

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(hetero meaning different) A mixture whose composition is not uniform throughout.

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elemental substance

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A pure substance composed of atoms of a single element. Compare compound.

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compounds

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A pure substance composed of two or more atoms of different elements. compare elemental substance.

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physical property

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A property of a substance that can change without the substance undergoing a chemical reaction; examples are density, boiling point, and color. Compare chemical property.