- 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
- 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
- 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
- temperature
- intensive property representing the hotness or coldness of matter
- 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