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Chemistry 1&2
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| Question | Answer |
|---|---|
| anything that has mass and takes up space | matter |
| the study of the properties of matter and how matter changes | chemistry |
| a single kind of matter that is pure, meaning it always has a specific makeup—or composition—and a specific set of properties | substance |
| a characteristic of a pure substance that can be observed without changing it into another substance | physical property |
| a characteristic of a pure substance that describes its ability to change into different substances | chemical property |
| a pure substance that cannot be broken down into any other substances by chemical or physical means | element |
| is the basic particle from which all elements are made | atom |
| a force of attraction between two atoms | chemical bond |
| groups of two or more atoms held together by chemical bonds | molecule |
| a pure substance made of two or more elements chemically combined in a set ratio | compound |
| shows the elements in the compound and the ratio of atoms | chemical formula |
| made of two or more substances, elements, compounds, or both—that are together in the same place but are not chemically combined | mixture |
| A mixture in which pure substances are unevenly distributed throughout the mixture. | heterogeneous mixture |
| A mixture in which substances are evenly distributed throughout the mixture. | homogeneous mixture |
| an example of a homogeneous mixture | solution |
| a measure of the force of gravity on you | weight |
| the measurement of the amount of matter in the object | mass |
| The system of units (SI) used by scientists to measure the properties of matter. | International System of Units |
| The amount of space that matter occupies | volume |
| relates the mass of a material in a given volume | density |
| any change that alters the form or appearance of matter but does not make any substance in the matter into a different substance | physical change |
| A change in matter that produces one or more new substances | chemical change |
| has a definite shape and a definite volume | solid |
| Solids that are made up of crystals | crystalline solid |
| the particles are not arranged in a regular pattern | amorphous solid |
| has a definite volume but no shape of its own | liquid |
| meaning “a substance that flows.” | fluid |
| the result of an inward pull among the molecules of a liquid that brings the molecules on the surface closer together | surface tension |
| a liquid’s resistance to flowing | viscosity |
| A state of matter with no definite shape or volume. | gas |
| The change in state from a solid to a liquid | melting |
| The temperature at which a substance changes from a solid to a liquid; the same as the freezing point, or temperature at which a liquid changes to a solid. | melting point |
| The change of state from liquid to solid | freezing |
| The change from a liquid to a gas | vaporization |
| The process that occurs when vaporization takes place only on the surface of a liquid. | evaporation |
| occurs when a liquid changes to a gas below its surface as well as at the surface | boiling |
| The temperature at which a liquid boils | boiling point |
| The opposite of vaporization | condensation |
| occurs when the surface particles of a solid gain enough energy that they form a gas | sublimation |
| the very small center core of an atom | nucleus |
| have a positive electric charge (indicated by a plus symbol, +) | proton |
| have no charge | neutron |
| move rapidly around the nucleus and have a negative electric charge | electron |
| the number of protons in its nucleus | atomic number |
| Atoms with the same number of protons and a different number of neutrons | isotope |
| the sum of the protons and neutrons in the nucleus of an atom | mass number |
| may be a diagram, a mental picture, a mathematical statement, or an object that helps explain ideas about the natural world | model |
| the average mass of all the isotopes of that element | atomic mass |
| A chart of the elements showing the repeating pattern of their properties. | periodic table |
| A one- or two-letter representation of an element. | chemical symbol |