crystalline solids Crystalline solids display a very
regular ordering of the particles (atoms, molecules,
or ions) in a three-dimensional structure called
the crystal lattice.
Dalton’s law Dalton’s law states that in a mixture of
gases (A +B +C.. .) the total pressure is simply
the sum of the partial pressures (the pressures
associated with each individual gas).
decomposition reactionsDecomposition reactions
are reactions in which a compound breaks down
into two or more simpler substances.
diamagnetism Diamagnetism is the repulsion of
a molecule from a magnetic field due to the
presence of all electrons in pairs.
diluteDilute is a qualitative term that refers to
a solution that has a relatively small amount of
solute in comparison to the amount of solvent.
dimensional analysis Dimensional analysis, some-
times called the factor label method, is a method
for generating a correct setup for a mathematical
problem.
dipole–dipole intermolecular force Dipole–
dipole intermolecular forces occur between polar
molecules.
double displacement (replacement) or metathesis
reaction A double displacement (replacement) or
metathesis reaction is a chemical reaction where
at least one insoluble product is formed from the
mixing of two solutions.
effective nuclear chargeThe overall attraction that
an electron experiences is called the effective nuclear
charge. This is less than the actual nuclear charge,
because other electrons interfere with the attraction
of the protons for the electron being considered.
electrochemistry Electrochemistry is the study
of chemical reactions that produce electricity
and chemical reactions that take place because
electricity is supplied.
electrochemical cells Electrochemical cells use
indirect electron transfer to produce electricity by
a redox reaction, or they use electricity to produce
a desired redox reaction.
electrode The electrode is that solid part of the
electrochemical cell that conducts the electrons
that are involved in the redox reaction.
electrode compartment The solutions in which the
electrodes are immersed are called the electrode
compartments.
electrolysis Electrolysis is a reaction in which
electricity is used to decompose a compound.
electrolyte An electrolyte is a substance which,
when dissolved in solution or melted, conducts an
electrical current.
electrolytic cells Electrolytic cells use electricity
from an external source to produce a desired
redox reaction.
electromagnetic spectrumThe electromagnetic
spectrum is radiant energy, composed of gamma
rays, X-rays, ultraviolet, visible, etc.
electron affinity The electron affinity is the energy
change that results from adding an electron to an
atom or ion.
electron captureElectron capture is a radioactive
decay mode that involves the capturing of an
electron from the energy level closest to the
nucleus (1s) by a proton in the nucleus.
electronegativityThe electronegativity (EN) is
a measure of the attractive force that an atom
exerts on a bonding pair of electrons.
electron cloud (density)The electron cloud or
density is a volume of space in which the proba-
bility of finding the electron is high.
electronic configurationThe electronic configura-
tion is a condensed way of representing the pat-
tern of electrons in an atom.
elementary stepElementary steps are the individual
reactions in the reaction mechanism or pathway.
empirical formula The empirical formula is a chemi-
cal formula that tells us which elements are present
in the compound and the simplest whole-number
ratio of elements.
endothermicEndothermic reactions absorb energy
from their surroundings.
endpointThe endpoint of a titration is the point sig-
naled by the indication that an equivalent amount of
base has been added to the acid sample, or vice versa.
enthalpyThe enthalpy change, ΔH, is the heat
gained or lost by the system during constant
pressure conditions.
excited stateAn excited state of an atom is an
energy state of higher energy.
entropy Entropy (S) is a measure of the disorder of
a system.
equilibrium constantThe quantity calculated when
the equilibrium concentrations of the chemical
species are substituted into the reaction quotient.
equivalence pointThe equivalence point is that
point in the titration where the moles of H+in the
acid solution have been exactly neutralized with
the same number of moles of OH−.360 Glossary