Course Glossary

how closely a measurement aligns with a correct value

inner transition metal in the bottom of the bottom two rows of the periodic table

element in group 1

element in group 2

positively charged particle consisting of two protons and two neutrons

negatively charged atom or molecule (contains more electrons than protons)

smallest particle of an element that can enter into a chemical combination

average mass of atoms of an element, expressed in amu

unit of mass equal to 1/12 of the mass of a carbon-12 atom

number of protons in the nucleus of an atom

compound that contains hydrogen and one other element, bonded in a way that imparts acidic properties to the compound (ability to release H+ ions when dissolved in water)

compound containing two different elements

positively charged atom or molecule (contains fewer electrons than protons)

unit of temperature; water freezes at 0°C and boils at 100 °C on this scale

element in group 16

change producing a different kind of matter from the original kind of matter

behavior that is related to the change of one kind of matter into another kind of matter

one-, two-, or three-letter abbreviation used to represent an element or its atoms

study of the composition, properties, and interactions of matter

pure substance that can be decomposed into two or more elements

attractive force between the nuclei of a molecule’s atoms and pairs of electrons between the atoms

composed of molecules formed by atoms of two or more different elements

volume of a cube with an edge length of exactly 1 cm

SI unit of volume

set of postulates that established the fundamental properties of atoms

ratio of mass to volume for a substance or object

versatile mathematical approach that can be applied to computations ranging from simple unit conversions to more complex, multi-step calculations involving several different quantities

negatively charged, subatomic particle of relatively low mass located outside the nucleus

substance that is composed of a single type of atom; a substance that cannot be decomposed by a chemical change

formula showing the composition of a compound given as the simplest whole-number ratio of atoms

number derived by counting or by definition

property of a substance that depends on the amount of the substance

unit of temperature; water freezes at 32 °F and boils at 212 °F on this scale

equals the magnitude of the charge of an electron (e) with e = 1.602 10⁻¹⁹ C

state in which matter has neither definite volume nor shape

vertical column of the periodic table

element in group 17

combination of substances with a composition that varies from point to point

combination of substances with a composition that is uniform throughout

compound containing one or more water molecules bound within its crystals

tentative explanation of observations that acts as a guide for gathering and checking information

element in the bottom two rows; if in the first row, also called lanthanide, or if in the second row, also called actinide

property of a substance that is independent of the amount of the substance

electrostatic forces of attraction between the oppositely charged ions of an ionic compound

SI unit of temperature; 273.15 K = 0 ºC

standard SI unit of mass; 1 kg = approximately 2.2 pounds

statement that summarizes a vast number of experimental observations, and describes or predicts some aspect of the natural world

when matter converts from one type to another or changes form, there is no detectable change in the total amount of matter present

measure of one dimension of an object

state of matter that has a definite volume but indefinite shape

unit of volume equivalent to 1000 cm³

realm of everyday things that are large enough to sense directly by human sight and touch

fundamental property indicating amount of matter

anything that occupies space and has mass

standard metric and SI unit of length; approximately 1.094 yards

realm of things that are much too small to be sensed directly

1/1,000 of a liter; equal to 1 cm³

matter that can be separated into its components by physical means

bonded collection of two or more atoms of the same or different elements

change in the state or properties of matter that does not involve a change in its chemical composition

characteristic of matter that is not associated with any change in its chemical composition

gaseous state of matter containing a large number of electrically charged atoms and/or molecules

how closely a measurement matches the same measurement when repeated

homogeneous substance that has a constant composition

procedure used to ensure that calculated results properly reflect the uncertainty in the measurements used in the calculation

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

SI unit of time

standards fixed by international agreement in the International System of Units (Le Système International d’Unités)

all of the measured digits in a determination, including the uncertain last digit

state of matter that is rigid, has a definite shape, and has a fairly constant volume

specialized language used to represent components of the macroscopic and microscopic domains, such as chemical symbols, chemical formulas, chemical equations, graphs, drawings, and calculations

intensive property representing the hotness or coldness of matter

well-substantiated, comprehensive, testable explanation of a particular aspect of nature

estimate of amount by which measurement differs from true value

standard of comparison for measurements

ratio of equivalent quantities expressed with different units; used to convert from one unit to a different unit

amount of space occupied by an object

force that gravity exerts on an object