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OpenStax Chem 1
This content is available for free at http://cnx.org/content/col11760/1.9
Term | Definition |
---|---|
Accuracy | how closely a measurement aligns with a correct value |
Atom | smallest particle of an element that can enter into a chemical combination |
Celsius (°C) | unit of temperature; water freezes at 0 °C and boils at 100 °C on this scale |
chemical change | change producing a different kind of matter from the original kind of matter |
chemical property | behavior that is related to the change of one kind of matter into another kind of matter |
chemistry | study of the composition, properties, and interactions of matter |
compound | pure substance that can be decomposed into two or more elements |
cubic centimeter (cm3 or cc) | volume of a cube with an edge length of exactly 1 cm |
cubic meter (m3) | SI unit of volume |
density | ratio of mass to volume for a substance or object |
Dimensional analysis | (also, factor-label method) versatile mathematical approach that can be applied to computations ranging from simple unit conversions to more complex, multi-step calculations involving several different quantities |
factor-label method | same as Dimensional analysis |
element | substance that is composed of a single type of atom; a substance that cannot be decomposed by a chemical change |
exact number | number derived by counting or by definition |
extensive property | property of a substance that depends on the amount of the substance |
Fahrenheit | unit of temperature; water freezes at 32 °F and boils at 212 °F on this scale |
gas | state in which matter has neither definite volume nor shape |
heterogeneous mixture | combination of substances with a composition that varies from point to point |
homogeneous mixture | (also, solution) combination of substances with a composition that is uniform throughout |
hypothesis | tentative explanation of observations that acts as a guide for gathering and checking information |
intensive property | property of a substance that is independent of the amount of the substance |
kelvin (K) | SI unit of temperature; 273.15 K = 0 ºC |
kilogram (kg) | standard SI unit of mass; 1 kg = approximately 2.2 pounds |
law | statement that summarizes a vast number of experimental observations, and describes or predicts some aspect of the natural world |
law of conservation of matter | when matter converts from one type to another or changes form, there is no detectable change in the total amount of matter present |
length | measure of one dimension of an object |
liquid | state of matter that has a definite volume but indefinite shape |
liter (L) | (also, cubic decimeter) unit of volume; 1 L = 1,000 cm3 |
macroscopic domain | realm of everyday things that are large enough to sense directly by human sight and touch |
mass | fundamental property indicating amount of matter |
matter | anything that occupies space and has mass |
meter (m) | standard metric and SI unit of length; 1 m = approximately 1.094 yards |
microscopic domain | realm of things that are much too small to be sensed directly |
milliliter (mL) | 1/1,000 of a liter; equal to 1 cm3 |
mixture | matter that can be separated into its components by physical means |
molecule | bonded collection of two or more atoms of the same or different elements |
physical change | change in the state or properties of matter that does not involve a change in its chemical composition |
physical property | characteristic of matter that is not associated with any change in its chemical composition |
plasma | gaseous state of matter containing a large number of electrically charged atoms and/or molecules |
precision | how closely a measurement matches the same measurement when repeated |
pure substance | homogeneous substance that has a constant composition |
rounding | procedure used to ensure that calculated results properly reflect the uncertainty in the measurements used in the calculation |
scientific method | path of discovery that leads from question and observation to law or hypothesis to theory, combined with experimental verification of the hypothesis and any necessary modification of the theory |
second (s) | SI unit of time |
SI units (International System of Units) | standards fixed by international agreement in the International System of Units (Le Système International d’Unités) |
significant figures | (also, significant digits) all of the measured digits in a determination, including the uncertain last digit |
solid | state of matter that is rigid, has a definite shape, and has a fairly constant volume |
symbolic domain | specialized language used to represent components of the macroscopic and microscopic domains, such as chemical symbols, chemical formulas, chemical equations, graphs, drawings, and calculations |
theory | well-substantiated, comprehensive, testable explanation of a particular aspect of nature |
uncertainty | estimate of amount by which measurement differs from true value |
unit | standard of comparison for measurements |
unit conversion factor | ratio of equivalent quantities expressed with different units; used to convert from one unit to a different unit |
volume | amount of space occupied by an object |
weight | force that gravity exerts on an object |