SAT Chemistry Vocabulary Flashcards
The outer energy level electron configuration characteristic of the inert gases.
noble gas structure (two electrons for helium; eight electrons for all others)
The glowing mass of gas and luminous particles produced by the burning of a gaseous substance.
flame
The number of molecules in 1 gram-molecular volume of a substance, or the number of atoms in 1 gram-atomic mass of an element; equal to 6.022169 x 10^23.
Avogadro’s number
adsorption
The adhesion (in an extremely thin layer) of the molecules of gases, of dissolved substances, or of liquids to the surfaces of solid or liquid bodies with which they come into contact.
W = Fs
Work. The product of the force exerted on a body and the distance through which the force acts; where W = work, F = force, and s = distance.
reduction
A chemical reaction that removes oxygen from a substance; a gain of electrons.
cathode
The electrode in an electrolytic cell that is negatively charged and attracts positive ions.
A unit for expressing the kinetic energy of subatomic particles.
MeV (Equals 10^6 electron volts.)
basic anhydride
A metallic oxide that forms a base when placed in water.
An organic hydroxyl compound formed by replacing one or more hydrogen atoms of a hydrocarbon with an equal number of hydroxyl (OH) groups.
alcohol
element
One of more than 100 “building blocks” of which all matter is composed. An element consists of atoms of only one kind and cannot be decomposed further by ordinary chemical means.
nonmetal
(a) An element whose oxide reacts with water to form an acid; (b) an element that takes on electrons and acquires a negative valence.
µ
abbreviation for atomic mass unit or micron
control rod
In a nuclear reactor, a rod of a certain metal such as cadmium, which controls the speed of the chain reaction by absorbing neutrons.
When a gas is made up of a mixture of different gases, the pressure of the mixture is equal to the sum of the partial pressures of the components.
Dalton’s law
The specific temperature at which a given solid changes into a liquid.
melting point
A natural or synthesized silicate used to soften water.
zeolite
A horizontal row of elements in the Periodic Table.
period
Equal volumes of gases under identical conditions of temperature and pressure contain equal numbers of particles (atoms, molecules, ions, or electrons).
Avogadro’s law
The average mean value of the isotopic masses of the atoms of an element. It indicates the relative mass of the element as compared with that of carbon-12, which is assigned a mass of exactly 12 atomic mass units.
atomic mass or relative atomic mass or atomic weight
Two or more forms of an element that differ only in the number of neutrons in the nucleus and hence in their mass numbers.
isotopes
atom
The smallest particle of an element that retains the properties of that element and can enter into a chemical reaction.
weak electrolyte
A substance that, when dissolved in water, ionizes only slightly and hence is a poor conductor of electricity.
nuclear fuel
A substance that is consumed during nuclear fission or fusion.
flammable
Capable of being easily set of fire; combustible (same as inflammable).
electronegativity
The numerical expression of the relative strength with which the atoms of an element attract valence electrons to themselves; the higher the number, the greater the attraction.
A bond in which electrons are closer to one atom than to another.
polar covalent bond (See also polar molecule.)
Gay-Lussac’s law
(Also Combining Volumes law.) The ratio between the combining volumes of gases and the product, if gaseous, can be expressed in small whole numbers.
pitchblende
A massive variety of uraninite that contains a small amount of radium.
Any reaction involving a change in nuclear structure.
nuclear reaction
Hess’s law
If a series of reactions are added together, the enthalpy change for the total reaction is the sum of the enthalpy changes for the individual steps.
A phase of matter that has a definite volume but takes the shape of the container.
liquid
atmosphere
The layer of gases surrounding Earth; also, a unit of pressure (1 atm = approximately 760 mm of Hg or torr).
The intensity or degree of heat of a body, measured by a thermometer.
temperature
The SI unit of pressure, equal to 1 newton per square meter.
pascal
Aufbau Principle
The principle that states that an electron occupies the lowest energy orbital that can receive it.
empirical formula
A formula that shows only the simplest ratio of the numbers and kinds of atoms, such as CH4.
salt
A compound, such as NaCl, made up of a positive metallic ion and a negative nonmetallic ion or radical.
A positive or negative number representing the charge that an ion has or an atom appears to have when its electrons are counted according to arbitrarily accepted rules: (1) electrons shared by two unlike atoms are counted with the more electronegative atom; (2) electrons shared by two like atoms are divided equally between the atoms.
oxidation number (state)
The science that deals with the constituents and all the changes in the atomic nucleus.
nucleonics
A nonmetallic oxide that, when placed in water, reacts to form an acid solution.
acidic anhydride
The ratio between the number of calories needed to raise the temperature of a certain mass of a substance 1 degree on the Celsius scale and the number of calories needed to raise the temperature of the same mass of water 1 degree on the Celsius scale.
specific heat
atomic number
The number that indicates the order of an element in the periodic system; numerically equal to the number of protons in the nucleus of the atom, or the number of negative electrons located outside the nucleus of the atom.
pH
A numerical expression of the hydrogen or hydronium ion concentration in a solution; defined as -log[H+] where [H+] is the concentration of hydrogen ions, in moles per liter.
A group of chemically united atoms that react as a unit and have an electric charge.
polyatomic ion
strong acid (or base)
An acid (or a base) capable of a high degree of ionization in water solution. Example: sulfuric acid (sodium hydroxide).
molar mass
The mass arrived at by the addition of the atomic masses of the units that make up a molecule of an element or compound. Expressed in grams/mole, the molar mass of a gaseous substance at STP occupies a molar volume equal to 22.4 liters.
nuclide
A species of atom characterized by the constitution of its nucleus.
A substance that, when added to a solution, makes changing the pH of the solution more difficult.
buffer
carbonated water
Water containing dissolved carbon dioxide.
matter
A substance that occupies space, has mass, and cannot be created or destroyed easily.
diffusion
The process whereby gases or liquids intermingle freely of their own accord.
The mass arrived at by the addition of the atomic masses of the units that make up a molecule of an element or compound.
molar mass (Expressed in grams/mole, the molar mass of a gaseous substance at STP occupies a molar volume equal to 22.4 liters.)
hydronium ion
A hydrated ion, H2O.H+ or H3O+.
dehydrating agent
A substance able to withdraw water from another substance, thereby drying it.
nitrogen fixation
Any process by which atmospheric nitrogen is converted into a compound such as ammonia or nitric acid.
amorphous
Having no definite crystalline structure.
Conversion of one element into another, either by bombardment or by radioactive disintegration.
transmutation
heavy water
(Also deuterium oxide, D2O) Water in which the hydrogen atoms are replaced by the atoms of the isotope of hydrogen, deuterium.
An organic compound containing the -CO- group.
ketone
fluorescence
Emission by a substance of electromagnetic radiation, usually visible, as the immediate result of (and only during) absorption of energy from another source.
An inorganic substance of definite composition found in nature.
mineral
A chemical reaction between an alcohol and an acid, in which an ester is formed.
esterification
spinthariscope
A device for viewing through a microscope the flashes of light made by particles from radioactive materials against a sensitized screen.
ionization equation
An equation showing the ions set free from an electrolyte.
The bonding of ions due to their opposite charges.
ionic bonding
The reaction of two molecules by loss of a molecule of water.
condensation polymerization
An electrode potential associated with the oxidation half-reaction.
oxidation potential
A device used to accelerate charged particles to high energies for bombarding the nuclei of atoms.
cyclotron
Lewis dot symbol
The chemical symbol (kernel) for an atom, surrounded by dots to represent its outer level electrons. Examples: K., Sr:. (Also called electron dot symbol.)
Of carbohydrates: the action of water in the presence of a catalyst upon one carbohydrate to form simpler carbohydrates.
hydrolysis
Referring to an element in the atomic form as it has just been liberated in a chemical reaction.
nascent (atomic)
glass
An amorphous, usually translucent substance consisting of a mixture of silicates. Ordinary glass is made by fusing together silica and sodium carbonate and lime; the various forms of glass contain many other silicates.
An equation showing a reaction among ions.
ionic equation
The sum of the atomic mass units of all the atoms (or ions) contained in a formula.
formula mass
Systeme International d’Unites
The modernized metric system of measurements universally used by scientists. There are seven base units: kilogram, meter, second, ampere, kelvin, mole, and candela.
analysis
The breaking down of a compound into two or more simpler substances.
deuterium
An isotope of hydrogen, sometimes called heavy hydrogen, with an atomic weight of 2.
The combining power of an element; the number of electrons gained, lost, or borrowed in a chemical reaction.
valence
volatile
Easily changed to a gas or a vapor at relatively low pressure.
A shortened name for a reaction that involves reduction and oxidation.
redox
plasma
Very hot ionized gases.
nuclear reaction
Any reaction involving a change in nuclear structure.
A numerical expression of the hydrogen or hydronium ion concentration in a solution.
pH
The flow of a gas through a small aperture.
effusion
electrode
A terminal of an electrolytic cell.
double bond
A bond between atoms involving two electron pairs. In organic chemistry: unsaturated.
volt
A unit of electrical potential or voltage, equal to the difference of potential between two points in a conducting wire carrying a constant current of 1 ampere when the power dissipated between these two points is equal to 1 watt (abbreviation: V).
efflorescence
The loss by a substance of its water of hydration on exposure to air at ordinary temperatures.
The specific temperature at which a given liquid and its solid form are in equilibrium.
freezing point
A property that determines how a substance will behave in a chemical reaction.
chemical property
A measure of the amount of solute that will dissolve in a given quantity of solvent at a given temperature.
solubility
Any of the five nonmetallic elements (fluorine, chlorine, bromine, iodine, astatine) that form part of Group 17 of the Periodic Table.
halogen
dew point
The highest temperature at which water vapor condenses out of the air.
The separation of the components in a mixture of liquids having different boiling points by vaporization.
fractional distillation
A change from gaseous to liquid state.
condensation
The energy needed to break a chemical bond and form a neutral atom.
bond energy
A bond between atoms involving two electron pairs.
double bond (In organic chemistry: unsaturated.)
Uniform; having every portion exactly like every other portion.
homogeneous
thermosetting
Capable of being permanently hardened by heat and pressure; resistant to the further effects of heat.
The same of the oxidation potential and reduction potential for a particular reaction.
reaction potential
A compound is composed of two or more elements chemically combined in a definite ration by weight.
Definite Composition law
activation energy
The minimum energy necessary to start a reaction.
acid
A water solution that has an excess of hydrogen ions; an acid turns litmus paper pink or red, has a sour taste, and neutralizes bases to form salts.
The layer of gases surrounding Earth.
atmosphere
An organic indicator; it is colorless in acid solution and red in the presence of OH- ions.
phenolphthalein
An organic salt formed by the reaction of an alcohol with an organic (or inorganic) acid.
ester
symbol
A letter or letters representing an element of the periodic table. Examples: O, Mn.
bond energy
The energy needed to break a chemical bond and form a neutral atom.
Multiple Proportions law
When any two elements, A and B, combine to form more than one compound, the different masses of B that unite with a fixed mass of A bear a small whole-number ratio to each other.
Heat cannot, of itself, pass from a cold body to a hot body.
Second Law of Thermodynamics
Any chemical taking part in a reaction.
reagent
petroleum (meaning “oil from stone”)
A complex mixture of gaseous, liquid, and solid hydrocarbons obtained from Earth.
anion
An ion or particle that has a negative charge and thus is attracted to a positively charged anode.
Cooling a hot piece of metal rapidly, as in water or oil.
quenching
thermoplastic
Capable of being softened by heat; may be remolded.
nucleonics
The science that deals with the constituents and all the changes in the atomic nucleus.
Penetrating radiations, of extremely short wavelength, emitted when a stream of electrons strikes a solid target in a vacuum tube.
X-rays
The process in which slow oxidation produces enough heat to raise the temperature of a substance to its kindling temperature.
spontaneous combustion (ignition)
An isotope of hydrogen, sometimes called heavy hydrogen, with an atomic weight of 2.
deuterium
A change that alters the atomic structures of the substances involved and results in different properties.
chemical change
lepton
An elementary particle; the electron and neutrino are believed to consist of leptons.
law (in science)
A generalized statement about the uniform behavior in natural processes.
qualitative analysis
A term applied to methods and procedures used to determine any or all of the constituent parts of a substance.
electroplating
Depositing a thin layer of (usually) a metallic element on the surface of another metal by electrolysis.
ionization
The process in which ions are formed from neutral atoms.
One of the two parts, either the reduction part or the oxidation part, of a redox reaction.
half-reaction
A substance that is readily oxidized.
reducing agent
A device for viewing through a microscope the flashes of light made by particles from radioactive materials against a sensitized screen.
spinthariscope
breeder reactor
A nuclear reactor in which more fissionable material is produced than is used up during operation.
photosynthesis
The reaction taking place in all green plants that produces glucose from carbon dioxide and water under the catalytic action of chlorophyll in the presence of light.
A subatomic particle found in the nucleus of the atom.
neutron (It has no charge and has the same mass as the proton.)
An element who’s oxide combines with water to form a base.
metal
The process involved in obtaining a metal from its ores.
metallurgy
The process of separating the ions in a compound by means of electrically charged poles.
electrolysis
A compound in whose molecules the atoms are arranged symmetrically so that the electric charges are uniformly distributed.
nonpolar compound
A phase of matter that has neither definite shape nor definite volume.
gas
A nuclear reaction that releases energy because of the splitting of large nuclei into smaller ones.
fission
An element that readily loses electrons and acquires a positive valence.
metal
One twelfth of the mass of a carbon-12 atom.
atomic mass unit
radioactive
Referring to substances that have the ability to emit radiations (alpha or beta particles or gamma rays).
phenolphthalein
An organic indicator; it is colorless in acid solution and red in the presence of OH- ions.
A gain of electrons.
reduction
paraffin series
The methane series of hydrocarbons.
A positively charged particle of electricity with about the same weight as the electron.
positron
flame
The glowing mass of gas and luminous particles produced by the burning of a gaseous substance.
van der Waals forces
Weak attractive forces existing between molecules.
heat capacity
(Also specific heat.) The quantity of heat, in calories, needed to raise the temperature of 1 gram of a substance 1 degree on the Celsius scale.
A change by which an element takes the place of another element in a compound.
displacement
The smallest particle of a substance that retains the physical and chemical properties of that substance.
molecule (Examples: He, BR2, H2O)
metal
(a) An element who’s oxide combines with water to form a base; (b) an element that readily loses electrons and acquires a positive valence.
A substance such as graphite, paraffin, or heavy water used in a nuclear reactor to slow down neutrons.
moderator
synthesis
The chemical process of forming a substance from its individual parts.
dry ice
Solid carbon dioxide.
Le Chatelier’s Principle
If a stress is placed on a system in equilibrium, the system will react in the direction that relieves the stress.
equilibrium
The point in a reversible reaction at which the forward reaction is occurring at the same rate as the opposing reaction.
A solution containing 1 mole of solute in 1,000 grams of solvent (indicated by m).
molal solution
The process of first vaporizing a liquid and then condensing the vapor back into a liquid, leaving behind the nonvolatile impurities.
distillation
A very rare, unstable, “triple-weight” hydrogen isotope (H^3) that can be made synthetically.
tritium
A salt formed by replacing part of the hydrogen ions of a dibasic or tribasic acid with metallic ions.
acid salt (Examples NaHS04, NaH2PO4.)
The quantity of matter that a substance possesses; it can be measured by its resistance to a change in position or motion, and is not related to the force of gravity.
mass
ore
A natural mineral substance from which an element, usually a metal, may be obtained with profit.
The weight of 1 milliliter of water at 4ºC.
gram
The use of radioactive carbon-14 to estimate the ages of ancient materials, such as archeological or paleontological specimens.
carbon dating
condensation
(a) A change from gaseous to liquid state; (b) the union of like or unlike molecules with the elimination of water, hydrogen chloride, or alcohol.
radioisotope
An isotope that is radioactive, such as uranium-235.
Kelvin scale
A temperature scale based on water freezing at 273 and boiling at 373 Kelvin units; its origin is absolute zero. Synonymous with absolute scale.
Avogadro’s number
The number of molecules in 1 gram-molecular volume of a substance, or the number of atoms in 1 gram-atomic mass of an element; equal to 6.022169 x 10^23. See also mole.
mass number
The nearest whole number to the combined atomic mass of the individual atoms of an isotope when tat mass is expressed in atomic mass units.
litmus
An organic substance, obtained from the lichen plant and used as an indicator; it turns red in acidic solution and blue in basic solution.
refraction (of light)
The bending of light rays as they pass from one material into another.
The addition of unsaturated molecules to each other.
additional polymerization
quenching
Cooling a hot piece of metal rapidly, as in water or oil.
Any process for converting atmospheric nitrogen into compounds, such as ammonia and nitric acid.
fixation of nitrogen
proteins
Large, complex organic molecules, with nitrogen an essential part, found in plants and animals.
enthalpy
The heat content of a chemical system.
Chemicals certified as having a standard of purity that demonstrates their fitness for use in medicine.
U.S.P. (United States Pharmacopeia) chemicals
All the certain digits, that is, those recorded in a measurement, plus one uncertain digit.
significant figures
brass
An alloy of copper and zinc.
Water containing dissolved carbon dioxide.
carbonated water
A negatively charged particle found outside the nucleus of the atom.
electron (It has a mass of 9.109 x 10^-28 gram.)
Referring to a compound composed of two elements, such as H2O.
binary
kindling temperature
The temperature to which a given substance must be raised before it ignites.
A temperature scale divided into 100 equal divisions and based on water freezing at 0º and boiling at 100º.
Celsius scale (Synonymous with centigrade.)
A U-tube (containing mercury or some other liquid) used to measure the pressure of a confined gas.
manometer
The combination of two or more orbitals to form new orbitals.
hybridization
The numerical expression of the relative strength with which the atoms of an element attract valence electrons to themselves; the higher the number, the greater the attraction.
electronegativity
A compound whose basic structure contains the benzene ring; it usually has a odor.
aromatic compound
chemical change
A change that alters the atomic structures of the substances involved and results in different properties.
quantitative analysis
A term applied to the methods and procedures used to determine the definite quantity or percentage of any or all of the constituent parts of a substance.
Added to drinking water to help prevent tooth decay.
fluoride
The gaseous phase of a substance that normally exists as a solid or liquid at ordinary temperatures.
vapor
Periodic law
The chemical properties of elements vary periodically with their atomic numbers.
Each electron orbital of an atom can be filled by only two electrons, which have opposite spins.
Pauli Exclusion Principle
The nucleus and all the electron shells of an atom except the outer one; usually designated by the symbol for the atom.
kernel (atomic)
antichlor
A substance used to remove the excess of chlorine in the bleaching process.
The center of the atom, which contains protons and neutrons.
nucleus
isomers
Two or more compounds having the same percentage composition but different arrangements of atoms in their molecules and hence different properties.
The electrode in an electrolytic cell that is negatively charged and attracts positive ions.
cathode
spectrum
The image formed when radiant energy is dispersed by a prism or grating into its various wavelengths.
orbital
A subdivision of a nuclear shell; it may contain none, one, or two electrons.
aldehyde
An organic compound formed by dehydrating oxidized alcohol; contains the characteristic -CHO group.
A weak chemical linkage between the hydrogen of one polar molecule and the oppositely charged portion of a closely adjacent molecule.
hydrogen bond
half-reaction
One of the two parts, either the reduction part or the oxidation part, of a redox reaction.
The union of like or unlike molecules with the elimination of water, hydrogen chloride, or alcohol.
condensation
A nuclear reactor in which more fissionable material is produced than is used up during operation.
breeder reactor
The chemical process of forming a substance from its individual parts.
synthesis
structural (graphic) formula
A pictorial representation of the atomic arrangement of a molecule.
Matter can be neither created nor destroyed (or weight remains constant in an ordinary chemical change).
Conservation of Matter law
freezing point
The specific temperature at which a given liquid and its solid form are in equilibrium.
decomposition
The breaking down of a compound into simpler substances or into its constituent elements.
An ion that has a positive charge.
cation
ductile
Capable of being drawn into thin wire.
Streams of electrons given off by the cathode of a vacuum tube.
cathode rays
A graduated glass tube into which gases are placed and subjected to an electric spark; used to measure the individual volumes of combining gases.
eudiometer
Applying a coating of zinc to iron or steel to protect the latter from rusting.
galvanizing
Referring to substances that have the ability to emit radiations (alpha or beta particles or gamma rays).
radioactive
normal salt
A salt in which all the hydrogen of the acid has been displaced by a metal.
The pressure exerted by a vapor given off by a confined liquid or solid when the vapor is in equilibrium with its liquid or solid form.
vapor pressure
A metallic oxide that forms a base when placed in water.
basic anhydride
anhydride
A compound derived from another compound by the removal of water; it will combine with water to form an acid (acidic anhydride) or a base (basic anhydride).
An atom or a group of combined atoms that carries one or more electric charges.
ion (Examples: NH4-, OH-.)
The product formed when the flux reacts with the impurities of an ore in a metallurgical process.
slag
dissociation (ionic)
The separation of the ions of an ionic compound due to the action of a solvent.
Kinetic-Molecular Theory
The theory that all molecules are in motion; this motion is most rapid in gases, less rapid in liquids, and very slow in solids.
reactant
A substance involved in a reaction.
mole
A unit of quantity that consists of 6.02x10^23 particles.
The breaking down of a compound into simpler substances or into its constituent elements.
decomposition
The valence shell electron pair repulsion model. It expresses the non-90º variations in bond angles for p orbitals in the outer energy levels of atoms in molecules because of electron repulsions.
VSEPR
An allotropic and very active form of oxygen, having the formula O3.
ozone
A vertical column of elements in the periodic table that generally has similar properties.
group
organic chemistry
The branch of chemistry dealing with carbon compounds, usually those found in nature.
Any unstable, elementary nuclear particle having a mass between that of an electron and that of a proton.
meson
The adhesion (in an extremely thin layer) of the molecules of gases, of dissolved substances, or of liquids to the surfaces of solid or liquid bodies with which they come into contact.
adsorption
alcohol
An organic hydroxyl compound formed by replacing one or more hydrogen atoms of a hydrocarbon with an equal number of hydroxyl (OH) groups.
Solid carbon dioxide.
dry ice
The solubility of a gas (unless the gas is very soluble) is directly proportional to the pressure applied to the gas.
Henry’s law
barometer
An instrument, invented by Torricelli in 1643, used for measuring atmospheric pressure.
inertia
The property of matter whereby it remains at rest or, if in motion, remains in motion in a straight line unless acted upon by an outside force.
kilocalorie
A unit of heat; the amount of heat needed to raise the temperature of 1 kilogram of water 1 degree on the Celsius scale.
kernel (atomic)
The nucleus and all the electron shells of an atom except the outer one; usually designated by the symbol for the atom.
displacement
A change by which an element takes the place of another element in a compound.
A reaction in which two chemical substances exchange ions with the formation of two new compounds.
double displacement
effervescence
The rapid escape of excess gas that has been dissolved in a liquid.
A term applied to the methods and procedures used to determine the definite quantity or percentage of any or all of the constituent parts of a substance.
quantitative analysis
meson
Any unstable, elementary nuclear particle having a mass between that of an electron and that of a proton.
Capable of being hammered or pounded into thin sheets.
malleable
specific gravity (mass)
The ratio between the mass of a certain volume of a substance and the mass of an equal volume of water (or, in the case of gases, an equal volume of air); expressed as a single number.
Emitting a steady, suffused light.
luminous
The chemical symbol (kernel) for an atom, surrounded by dots to represent its outer level electrons.
Lewis dot symbol or electron dot symbol (Examples: K., Sr:.)
polyatomic ion
A group of chemically united atoms that react as a unit and have an electric charge.
Having no definite crystalline structure.
amorphous
London force
The weakest of the van der Waals forces between molecules. These weak, attractive forces become apparent only when the molecules approach one another closely (usually at low temperatures and high pressure). They are due to the way the positive charges of one molecule attract the negative charges of another molecule because of the charge distribution at any one instant.
The union of the hydrogen ion of an acid and the hydroxyl ion of a base to form water.
neutralization
An atmospheric pressure of 760 millimeters or torr or 1 atmosphere (mercury pressure) and a temperature of 0ºC (273 K) (abbreviation: STP).
standard conditions
A substance composed of two or more components, each of which retains its own properties.
mixture
IUPAC
International Union of Pure and Applied Chemistry, an organization that establishes standard rules for naming compounds.
To vaporize directly from the solid to the gaseous state, and then condense back to the solid.
sublime
emulsion
A suspension of fine particles or droplets of one liquid in another, the two liquids being immiscible in each other; the droplets are surrounded by a colloidal (emulsifying) agent.
Referring to a chemical reaction that results in an overall absorption of heat from its surroundings.
endothermic
The chemical process by which oxygen is attached to a substance.
oxidation
Fahrenheit scale
The temperature scale that has 32º as the freezing point of water and 212º as the boiling point.
Emission by a substance of electromagnetic radiation, usually visible, as the immediate result of (and only during) absorption of energy from another source.
fluorescence
volume
The amount of three-dimensional space occupied by a substance.
In metallurgy: a substance that helps to melt and remove the solid impurities as slag.
flux
tincture
An alcoholic solution of a substance, such as a tincture of iodine.
Definite Composition law
A compound is composed of two or more elements chemically combined in a definite ration by weight.
density
The mass per unit volume of a substance; the mathematical formula is D = m/V, where D = density, m = mass, and V = volume.
electron dot symbol
Lewis dot symbol. The chemical symbol (kernel) for an atom, surrounded by dots to represent its outer level electrons. Examples: K., Sr:.
The total energy of the universe is constant and cannot be created or destroyed.
First Law of Thermodynamics
Containing no water.
anhydrous
hypothesis
A possible explanation of the nature of an action or phenomenon; a hypothesis is not as completely developed as a theory.
A form of molecular energy; it passes from a warmer body to a cooler one.
heat
A shorthand method of showing the changes that take place in a chemical reaction.
equation
A phase of matter that has a definite size and shape.
solid
Usually, a strong base, such as sodium hydroxide or potassium hydroxide.
alkali
The energy released by spontaneously or artificially produced fission, fusion, or disintegration of the nuclei of atoms.
nuclear energy (sometimes called atomic energy)
beta particles
High-speed, negatively charged electrons emitted in radiation.
noble gas structure
The outer energy level electron configuration characteristic of the inert gases – two electrons for helium; eight electrons for all others.
Ideal Gas law
Any gas that obeys the gas laws perfectly. No such gas actually exists.
A type of radiation consisting of high-energy waves that can pass through most materials.
gamma rays
sublime
To vaporize directly from the solid to the gaseous state, and then condense back to the solid.
An explanation used to interpret the “mechanics” of nature’s actions.
theory (A theory is more fully developed than a hypothesis.)
The formula weight, in grams, of a substance.
gram-formula weight
reaction
A chemical transformation or change. The four basic types are combination (synthesis), decomposition (analysis), single replacement or single displacement, and double replacement or double displacement.
relative humidity
The ratio, expressed in percent, between the amount of water vapor in a given volume of air and the amount the same volume can hold when saturated at the same temperature.
slag
The product formed when the flux reacts with the impurities of an ore in a metallurgical process.
A device in which a controlled chain reaction of fissionable material can be produced.
nuclear reactor
A subdivision of a nuclear shell; it may contain none, one, or two electrons.
orbital
normal solution
A solution that contains 1 gram of H+ (or its equivalent: 17g of OH-, 23g of Na+, 20g of Ca2+, etc.) in 1 letter of solution (indicated by N).
electrolyte
A liquid that will conduct an electric current.
ionic bonding
The bonding of ions due to their opposite charges.
immiscible
Referring to the inability of two liquids to mix.
anhydrous
Containing no water.
An element that takes on electrons and acquires a negative valence.
nonmetal
A natural mineral substance from which an element, usually a metal, may be obtained with profit.
ore
A subatomic particle found in the nucleus that has a positive charge.
proton
destructive distillation
The process of heating an organic substance, such as coal, in the absence of air to break it down into solid and volatile products.
thermochemical equation
An equation that includes values for the calories absorbed or evolved.
critical mass
The smallest amount of fissionable material that will sustain a chain reaction.
crystalline
Having a definite molecular or ionic structure.
The difference in potential between an electrode and the solution in which it is immersed.
electrode potential
The numerical expression of the relative strength with which the atoms of an element attract valence electrons to themselves.
electronegativity (The higher the number, the greater the attraction.)
Easily changed to a gas or a vapor at relatively low pressure.
volatile
A substance that, when dissolved in water, ionizes only slightly and hence is a poor conductor of electricity.
weak electrolyte
oxidation potential
An electrode potential associated with the oxidation half-reaction.
endothermic
Referring to a chemical reaction that results in an overall absorption of heat from its surroundings.
indicator
A dye that shows one color in the presence of the hydrogen ion (acid) and a different color in the presence of the hydroxyl ion (base).
spectroscope
An instrument used to analyze light by separating it into its component wavelengths.
physical change
A change that doe not involve any alteration in chemical composition.
The atomic mass, in grams, of an element.
gram-atomic mass
malleable
Capable of being hammered or pounded into thin sheets.
Heating an ore (usually a sulfide) in an excess of air to convert the ore to an oxide, which can then be reduced.
roasting
A hydrated ion.
hydronium ion (H2O.H+ or H3O+)
Conservation of Energy law
Energy can be neither created nor destroyed, so that the energy of the universe is constant.
