| word |
def |
| law of conservativeof mass |
the law that states that mass cannot be created or destroyed in ordinary chemical and physical changes |
| law of definite proportions |
the law that states that a chemical compound always contains the same elements in exactly the same proportions by weight or mass |
| law of multiple proportions |
the law that states that when two elements combine to form two or more compounds, the mass of one element that combines with a given mass of the other is in the ratio of small whole numbers |
| atom |
the smallest unit of an element that maintains the chemical properties of that element |
| nuclear forces |
the interaction that binds protons and neutrons, protons and protons, and neutrons and neutrons together in a nucleus |
| atomic number |
the number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element |
| average atomic mass |
the weighted average of the masses of all naturally occurring isotopes of an element |
| isotopes |
an atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass) |
| mass number |
the sum of the numbers of protons and neutrons in the nucleus of an atom |
| electromagnetic spectrum |
all of the frequencies or wavelengths of electromagnetic radiation |
| excited state |
a state in which an atom has more energy than it does at its ground state |
| frequency |
the number of cycles or vibrations per unit of time; also the number of waves produced in a given amount of time |
| ground state |
the lowest energy state of a quantized system |
| wavelength |
the distance from any point on a wave to an identical point on the next wave |
| angular momentum quantum number |
the quantum number that indicates the shape of an orbital |
| Heisenberg uncertainty principle |
the principle that states that determining both the position and velocity of an electron or any other particle simultaneously is impossible |
| magnetic quantum number |
the quantum number that corresponds to the alignment of the angular momentum component with a magnetic field |
| orbital |
a region in an atom where there is a high probability of finding electrons |
| principal quantum number |
the quantum number that indicates the energy and orbital of an electron in an atom |
| quantum numbers |
a number that specifies the properties of electrons |
| quantum theory |
the study of the structure and behavior of the atom and of subatomic particles from the view that all energy comes in tiny, indivisible bundles |
| spin quantum number |
the quantum number that describes the intrinsic angular movement of a particle |
| Aufbau principle |
the principle that states that the structure of each successive element is obtained by adding one proton to the nucleus of the atom and one electron to the lowest-energy orbital that is available |
| electron configuration |
the arrangement of electrons in an atom |
| highest occupied level |
Highest number of electrons |
| Hund’s rule |
the rule that states that for an atom in the ground state, the number of unpaired electrons is the maximum possible and these unpaired electrons have the same spin |
| inner-shell electrons |
one of the lowest energy shells in an atom. It is therefore a localized electron which does not contribute to bonding or conduction. |
| noble gases |
one of the elements of Group 8 of the periodic table (helium, neon, argon, krypton, xenon, and radon); noble gases are unreactive |
| noble gas configuration |
An electron structure of an atom or ion in which the outer electron shell contains eight electrons, corresponding to the electron configuration of a noble gas, such as neon or argon. |
| Pauli exclusion principle |
the principle that states that two particles of a certain class cannot be in exactly the same energy state |
Ch.18 LTI-MA 509
