Page 335 - Theory and Problems of BEGINNING CHEMISTRY

324 GLOSSARY

spectator ions ions that are in solution at the start of a reaction and wind up unchanged (as the same ion in
solution).
stable resistant to reaction.
standard conditions for gases 0 C and 1 atm pressure; STP.
◦
standard exponential notation exponential notation with the coefficient having a value of 1 or more but less
than 10.
◦
standard state the state of a substance in which it usually occurs at 25 C and 1 atm pressure. For example, the
standard state of elementary oxygen is O 2 molecules in the gaseous state.
◦
standard temperature and pressure 0 C and 1 atm pressure.
Stock system the nomenclature system using oxidation numbers to differentiate between compounds or ions
of a given element.
stoichiometry the science of measuring how much of a substance can be produced from given quantities of
others.

STP standard temperature and pressure for gases; 0 C and 1 atm pressure.
◦
stress a change in conditions imposed on a system at equilibrium.
strong acid an acid that reacts completely with water to form ions.
structural formula a formula in which all atoms are shown with their covalently bonded electron pairs repre-
sented by lines; graphical formula.
subdivision particle size of solids.
sublimation changing directly from a solid to a gas.

subshell the set of electrons in an atom all having the same value of n and the same value of l.
substance (pure substance) an element or a compound.
substitution reaction the reaction of a free element plus a compound in which the free element replaces one
of the elements in the compound and enters the compound itself. For example: 2 Na + ZnCl 2 −→ 2 NaCl + Zn
−
superoxide ion O 2 ion.
supersaturated solution a solution holding more solute than the solution can hold stably at the particular
temperature.
symbol one- or two-letter representation of an element or an atom of an element. The first letter of a symbol is
capitalized; the second letter, if any, is lowercase.

system portion of matter under investigation, such as the contents of a particular beaker.
t symbol for Celsius temperature.

T symbol for absolute temperature.
temperature the intensity of heat in an object. The property that determines the direction of spontaneous heat
flow when bodies are connected thermally.

ternary compound a compound of three elements.
tertiary amine an amine with three R groups; R 3 N.
theory an accepted explanation of experimental results.
thermochemistry the science that investigates the interaction of heat and chemical reactions.