absorption spectrum
a graph showing the absorption of electromagnetic energy by atoms when electrons move from lower to higher energy levels
a substance that when added to water increases the hydrogen ion (H+) concentration (Arrhenius theory), or a substance that donates a proton (H+) during a chemical reaction (Bronsted-Lowry theory)
acid-base reaction
a reaction between and acid and a base
actual yield
the amount of product that is experimentally produced and/or recovered
stirring, moving, shaking up
a solution: having a pH of more than 7
the quantitative measure of the capacity of water or any solution to neutralize an acid
a substance that behaves both as an acid and as a base
the process of organizing and making sense out of the results of the experiment and comparing this to the original hypothesis; can lead to a modification of the hypothesis
to closely observe in order to understand; looking for patterns or relationships
a negatively charged ion created when an element gains one or more electrons
watery, containing water
Arrhenius acid
substance that when added to water increases the hydrogen ion (H+) concentration
Arrhenius base
substance that when added to water increases the hydroxide ion (OH-) concentration
atomic number
the number of protons in the nucleus of the atom
a unit of pressure equal to the air pressure at sea level; abbreviated ATM
It equals the amount of pressure that will support a column of mercury 760 millimeters high at 0 degrees Celsius under standard gravity, or 14.7 pounds per square inch (1.01325 × 105 pascals).
Avogadro's number
the number of particles (atoms, ions, molecules, formula units) in a mole of a substance
It is equal to 6.02 × 1023.
average atomic mass
the weighted average of the atomic masses of the naturally occurring isotopes of an element
a soluble compound that dissociates one or more hydroxide ions, (OH-) in water (Arrhenius theory), or a substance that accepts H+ ions (Bronsted-Lowry theory)
binary acid
acids that contains hydrogen and one other element
binary ionic compound
a salt made up of only two elements in which both elements are ions, a cation and an anion
bonding group of electrons
electrons shared by the central atom and any atom to which it is bonded
A single bond, double bond, and triple bond all count as a single bonding group of electrons.
Boyle's Law
at constant temperature the volume occupied by a gas is inversely proportional to the applied pressure
Bronsted-Lowry acid
substance that donates a proton (H+) during a chemical reaction
Bronsted-Lowry base
substance that accepts a proton (H+) during a chemical reaction
a device used to measure the heat of a chemical reaction
the amount of heat that is generated or absorbed in a chemical reaction
a positively charged ion created when an element loses one or more electrons
chemical bonding
when atoms gain, lose, or share electrons to reach octet in the outer orbital
chemical change
involves a NEW substance being formed
These types of changes are usually not reversible.
chemical equation
a symbolic representation of a chemical reaction; a representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products
chemical property
describes how the substance reacts with something else
the number in front of a chemical formula in a balanced chemical equation that indicates how many particles, or moles, of each reactant and product are involved in a reaction
comparative investigation
an investigation where observations are made that compare two objects or phenomena
a relatively large quantity of substance present in a unit amount of mixture
the number of molecules of a substance in a given volume
a statement that adequately explains or solves the original problem based on the results of scientific experimentation
the transfer of thermal energy between neighboring molecules in a substance due to a temperature gradient
the unit of milliamps or amps
conjugate acid
substance formed when a base gains a hydrogen ion; considered an acid because it can lose a hydrogen ion to reform the base
conjugate base
substance formed when an acid loses a hydrogen ion; considered a base because it can gain a hydrogen ion to reform the acid
movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat
core electrons
electrons not in the outer most electron shell
They are closer to the nucleus and are not involved in bonding, unless shells above are lost.
covalent bond
a chemical bond that involves sharing of electron pairs
covalent compound
a molecule formed by bonds between two non-metal atoms, in which the atoms share one or more pairs of valence electrons
Dalton's Law
law stating that the pressure exerted by a mixture of gases equals the sum of the partial pressures of the gases in the mixture
information gathered by using the senses or numbers and measurements
decomposition reaction
a chemical reaction in which a more complex substance breaks down into its more simple parts

delocalized electrons
electrons in a molecule that are not associated with a single atom or one covalent bond
Delocalized electrons are contained within an orbital that extends over several adjacent atoms.
the mass of a substance divided by its volume D = Mass/Volume
dependent variable
a characteristic of an experiment that is a result of the effect or influence of an independent variable
descriptive investigation
an investigation where observations of new phenomena are recorded and catalogued
diatomic molecule
molecule made up of only two atoms, either the same or different elements
describes the mixing of gasses and is the result of the random movement of gas molecules
a solution containing a relatively small quantity of solute as compared with the amount of solvent
process of decreasing the concentration of a solute in solution, usually simply by mixing with more solvent (usually water)
a process in which ionic compounds separate or split into smaller particles, ions, or radicals, usually in a reversible manner
when a solution is made, as by mixing a substance with a liquid; pass into solution
double bond
when an atom is bonded to another atom by two pair of electrons
double covalent bond
type of covalent bond in which two atoms share four electrons
double replacement reaction
a reaction in which the parts of two compounds switch places to form two new compounds
a mechanical property used to describe the extent to which materials can be deformed plastically without fracture, often characterized by the material's ability to be stretched into a wire
long lasting, capable of withstanding scrutiny
electrical conductivity
a measure of a material's ability to conduct an electric current
a chemical compound that disassociates into ions in a solution or when molten, and is able to conduct electricity
electromagnetic energy
the potential energy of an electric or magnetic field
electromagnetic waves
the movement of electric charge; in a vacuum these waves travel at the speed of light (c = 3 x108 m/s)
part of the atom having a negative charge
electron configuration
the arrangement of electrons of an atom
electron dense area
any area around a central atom that has electrons, whether it be another atom or unbound electron pairs
electron dot structure
diagrams that show the bonding between the atoms in molecules
electron pair geometries
the name of the geometry of the electron-pairs on the central atom, whether they are bonding or nonbonding
a measure of the relative tendency of an atom to attract electrons to itself when chemically combined with another atom
electrostatic repulsion
the repelling of atoms due to their electrons’ charges
the process of a substance being released or emitted
emission line
bright line in a specific location of the spectrum of an energized, radiating element, corresponding to emission of light at a certain frequency
A heated gas in a glass container produces emission lines in its spectrum.
emission spectrum
a graph showing the emission of electromagnetic energy by atoms when electrons move from higher to lower energy levels
empirical data
data collected from reliable measurement or observation
empirical formula
formula showing the simplest ratio of elements in a compound
a chemical reaction that absorbs heat energy from its surroundings
energy level
the area where electrons are located in an atom
Each energy level holds a specific amount of energy; therefore, each energy level can only hold a certain number of electrons.
enthalpy, H
the amount of energy stored within a substance
the state of a chemical reaction in which its forward and reverse reactions occur at equal rates so that the concentration of the reactants and products does not change with time
objective findings during a scientific investigation that either support or do not support the hypothesis
excess reactant
the reactant that does not get used up completely in an otherwise complete reaction
This reactant will have leftovers at the end of a reaction. Also, "excess reagent"
excited state
the electrons of an atom are in a higher energy level than the atoms in a ground state
a chemical reaction that releases heat energy to its surroundings
expanded valence
valence shells that have more than eight electrons
experimental investigation
an organized scientific investigation that is designed to test the hypothesis; includes independent and dependent variables and only attempts to test one variable at a time
statement that helps make something comprehensible (understandable)
the symbol for frequency measured in hertz, Hz or sec-1
capable of being shown to be false if it is untrue
formal charge
the difference between the number of valance electrons of each atom and the number of bonds and lone pairs
formula unit
the smallest ratio of atoms making up the compound
the number of wave cycles per unit time measured in hertz, Hz or sec-1
a substance that has no definite shape or volume
ground state
the state of lowest energy in which an atom can exist; when an atom is in ground state, the electrons are in the lowest energy levels possible
the hydrogen ion concentration in solution, may also be represented by the hydronium ion H3O+
a form of energy that is transferred between two objects due to a temperature difference between them
Heat of formation, Hf
the amount of energy required or released when one mole of a compound is formed from its elements
Heat of reaction, Hrxn
the enthalpy change that occurs in a system when one mole of matter is transformed by a chemical reaction under standard conditions
highly reliable
something that has been researched frequently that displays little or no change after repeated experiments
having a uniform composition or structure
hydrogen bonds
a weak bond that forms between molecules that contain a hydrogen that is bonded to a highly electronegative element such as O, F, and N
Hydrogen is partially positive in these compounds and forms a weak bond with partial negative elements of molecules.
hydronium ion
H30+, formed by the attachment of a proton to a water molecule, occurs in solutions of acids and behaves like a hydrogen
a proposed explanation, based on observation and research, to a scientific question
ideal gas
a hypothetical gas with molecules of insignificant size that are not attracted to each other
independent variable
a characteristic of an experiment that determines the value of the other (dependent) variable(s)
a chemical detector that changes color to signify the presence of an acid or base
a substance is incapable of forming a solution
the International Union of Pure and Applied Chemistry (IUPAC, ) is an international federation of National Adhering Organizations that represents chemists in individual countries
It is a member of the International Council for Science (ICSU). The international headquarters of IUPAC is located in Zürich, Switzerland.
method of gathering data by observation, testing a hypothesis, or comparing in order to solve a problem or answer a question
an atom or molecule which has gained or lost one or more of its valence electrons, giving it a net positive or negative electrical charge
ionic bond
the bond between a metal cation and a nonmetal anion
The bond involves a transfer of electrons to complete both elements valence shell resulting in a neutral species.
ionic compound
a compound that is held together by ionic bonds
to convert totally or partially into ions
ionization energy
the energy required to remove an electron from an atom
form of element with same atomic number: each of two or more forms of a chemical element with the same number of protons but with different numbers of neutrons
iterative process
any process that can result in the repetition of previous steps after revisions based on observations of collected data
kilopascal kPa
equal to 10 pascals
kinetic energy
the energy an object has because of its motion
a setting in which scientific work is performed
law of conservation of energy
states that energy may neither be created nor destroyed
law of conservation of mass
a law that states mass is neither created or destroyed
Stated another way: there is no change in total mass during a chemical reaction.
Lewis valence dot diagram
representation of atoms showing valence electrons as dots around the element symbol
limiting reactant
the reactant that will run out first in a chemical reaction
Also, “excess reagent”
a molecular geometry model in the VSEPR theory with one atom at the center and a combination of two electron dense regions (atoms or lone pairs) attached to the central atom
logarithmic scale
a scale of measurement displays the value of a using intervals corresponding to orders of magnitude, rather than a standard linear scale
lone electron pair
unbound electrons sometimes present in a molecule
a description of the way light interacts with the surface of a crystal, rock, or mineral and generally implies radiance, gloss, or brilliance
refers to a material's ability to deform under compressive stress; this is often characterized by the material's ability to form a thin sheet by hammering, rolling, or molding into different forms
mass number
the sum of the weights of both the neutrons and protons in the atom
metallic bond
the electromagnetic interaction between delocalized electrons and the metallic nuclei within metals
a replica, representation, or description designed to show how an object, system, or idea is constructed or how it works
molar mass
the mass in grams, of one mole of a substance
a concentration unit, defined to be the number of moles of solute divided by the number of liters of solution
measurement for the amount of a substance; 1 Mole of a substance represents 6.02 x 1023 representative particles of that substance
a compound that is neutral and covalently bonded
molecular formula
shows the number of atoms of each element present in a molecule
molecular geometry
the three dimensional arrangement of atoms in molecules
molecular structure
the three-dimensional arrangement of the atoms that constitute a molecule; the shape of the molecule
natural phenomena
any observable occurrence of the natural world
a reaction between acid and base which neutralizes both and results in the formation of water plus a salt
neutralization reaction
a chemical reaction between an acid and a base that produces a salt and water
non-bonding pairs of electrons (lone pairs)
a pair of electrons on an individual atom that are not shared with another atom
a chemical compound that does not separate into ions in a solution or when molten, and is not able to conduct electricity
a bond in which there is little to no difference in electronegativities between the bonding atoms that allow electrons to be shared equally between the atoms
There are no resulting partial charges. does not dissociate into ions in solution
not supported
 not confirmed, sustained or maintained
nuclear chemistry
the field of chemistry dealing with radioactivity, nuclear processes and nuclear properties
nuclear fission
a nuclear reaction in which a heavy nucleus (such as uranium) splits into two lighter nuclei (and possible some other radioactive particles as well)
nuclear fusion
the process in which light atoms such as those of hydrogen and deuterium combine and form heavier atoms, releasing a great amount of energy
the hydroxide ion concentration in solution
a method of data collection that includes collecting quantitative and qualitative data
a group of eight
octet rule
a general "rule of thumb" that states that atoms are most stable when their outermost energy level (shell) contains eight electrons
Atoms tend to bond in a way to have eight electrons in their valence shells.
space in atom occupied by electrons
the loss of electrons
oxidation number
the resulting charge an atom will end up when it gains or loses electrons
oxidation – reduction reaction (redox)
a reaction in which electrons are transferred from a donor (the reducing agent) to an acceptor molecule (the oxidizing agent)
acids that have at least one oxygen atom in the formula
a unit of measure for air or gas pressure; 256 pascals equal one inch of water column (IWC); one IWC = .4 pascal
pass into or through
percent composition
expresses the weight ratio between different elements in a compound
percent yield
the ratio of actual yield to theoretical yield in percent form
particles of light energy
particles of light energy
concentration of hydrogen ions in solution
pH scale
shows the relationship between [H+] and [OH-] and can be used to determine if a substance is acidic or basic
physical property
describes the substance itself (what does the substance looks like, what are some characteristics to describe the substance)
a polar bond in which there is a large difference in electronegativities between the bonding atoms and causes the electrons to be more attracted to one atom than the other
This results in partial positive on one side of the bond and partial negative on the other side of the bond because the electrons are unequally shared between the bonding elements.
polyatomic ion
molecule made up of 2 or more atoms that are considered an ionic group or a molecule with a charge
insoluble product that results from a chemical reaction
precipitation reaction
chemical reaction that forms a precipitate; usually between two ionic compounds
using given information to guess what information may be missing or come next in an event
letters placed before a term to modify the meaning
In chemistry, prefixes indicate the number of elements in a certain molecule.
the force caused by pressing between two objects
The most common unit for pressure is Pascals (Pa) or kiloPascals (kPa), but it can also be measured in atmospheres (the pressure of the Earth's atmosphere at the surface).

1 atmosphere = 101.3 kPa
substance(s) formed as a result of a process; located on the right side of the arrow
a problem that cannot be answered by simple observation or by research
(1) a process in which energetic particles or waves travel through a medium or space
(2) energy that is transmitted in the forms of waves or particles
(3) energy emitted from a material which is due to the heat of the material, the characterics of which depend on its temperature
radioactive decay
the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles (ionizing radiation)
the starting material in a process; located on the left side of the arrow
the gain of electrons by a compound or ion
relative abundance
the abundance of isotopes of a chemical element as naturally found on a planet
experimental processes using repetition to confirm previous experimental findings
resonance structures
multiple representations of a molecule in which pairs of electrons can be in alternate positions, theoretically resonating between different options
part of the element name that is used in formula writing
ionic compound that can be formed by replacing one or more of the hydrogen ions of an acid with another positive ion
contains the maximum amount of solute dissolved in solvent at a specific temperature
scientific investigation
a structured way for  investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge
scientific methodology
an organized system used by scientists to perform investigations that help to develop an accurate explanation of observations
single covalent bond
type of covalent bond in which two atoms share a pair of electrons
single replacement reaction
a reaction in which a single uncombined element replaces another in a compound
dissolves in a specific solvent
the quantity of a particular substance that can dissolve in a particular solvent
solubility curve
a graph showing the relationship between solubility and temperature
solubility graph
visual representation of the the amount of solute a solvent can hold at various temperatures
a liquid, solid, or gas that is dissolved by another solid, liquid, or gas resulting in a solution
homogeneous mixture between two or more substances
a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute resulting in a solution
specific heat
the heat required to raise the temperature of one gram of a substance one degree centigrade
Standard Temperature and Pressure (1atm and 0°C)
a division of an energy level
Sublevels are denoted by the letters, s, p, d or f.
the number to the bottom right of an element symbol that indicates how many atoms of that element are found in a single particle of that formula
Alternatively, it indicates how many moles of that element are found in a mole of the substance represented by the formula.
surface tension
property of liquids that results from stronger bonds between molecules at the surface of the liquid than in the rest of the liquid because the molecules at the top are not surrounded by other like molecules
It is a result of cohesive forces of molecules and is most strong in water.
contains more than the theoretical maximum amount of solute dissolved in solvent
confirmed, sustained or maintained
surface area
the area of a particle exposed to a liquid or air
synthesis reaction
a chemical reaction in which two or more simple substances combine to form a more complex substance
application of knowledge to solve problems or create new tools
how hot or cold something is; when talking about gas molecules, it is related to kinetic energy
Faster molecular movement-higher temperature
Slower molecular movement-lower temperature
not final, definite or validated
something that can be investigated or analyzed
a molecular geometry model in the VSEPR theory with one atom at the center and a combination of four electron dense regions (atoms or lone pairs) attached to the central atom
theoretical yield
the maximum amount of product that a reaction can yield, usually found by stoichiometry
thermal conductivity
the property of a material that indicates its ability to conduct heat
the pressure exerted by 1mm of mercury, Hg; standard atmospheric pressure is 760 torr
the transformation of the atom of one chemical element into the atom of another by disintegration or nuclear bombardment
patterns that can be observed by looking at data
trigonal planar
a molecular geometry model in the VSEPR theory with one atom at the center and a combination of three electron dense regions (atoms or lone pairs) attached to the central atom
triple bond
when an atom is bonded to another atom by three pair of electrons
triple covalent bond
type of covalent bond in which two atoms share six electrons
universal solvent
a label for water because it can dissolve so many different solutes and because of its abundance
However, it cannot dissolve all solutes.
can dissolve more solute at a specific temperature
valence electron
electrons in the outer most shell that are involved in bonding
valence shell electron pair repulsion (VSEPR) theory
a model in chemistry used to predict the shape of individual molecules based upon the extent of electron-pair electrostatic repulsion
something that may be changed or manipulated during an investigation
the amount of 3-dimensional space something takes up; measured in Lters or cm3 (1 Liter = 1000 cm3)
the distance between two points on adjacent waves that have the same phase
weighted average
an average that takes into account the proportional relevance of each component, rather than treating each component equally
having been in accepted existence for a long time; standing up to scrutiny