Download Vocabulary Terms Defined

Chapter 4 Chemistry Terms – in order by page in the text book (27 terms Listed on page 117)
electromagnetic radiation (91) a form of energy emitted and absorbed by charged particles, which
exhibits wave-like behavior as it travels through space. EMR has both electric and magnetic field
components
electromagnetic spectrum (91) is the range of all possible frequencies of electromagnetic radiation. The
“electromagnetic spectrum” of an object has a different meaning, and is instead the characteristic
distribution of electromagnetic radiation emitted or absorbed by that particular object.
wavelength (91) () is the distance between corresponding points on adjacent waves.
frequency (92) (f; The textbook uses  ) is defined as the number of waves that pass a given point in a
specific time, usually one second.
photoelectric effect (93) refers to the emission of electrons from a metal when light shines on the metal
(solar cell)
quantum (93) the minimum quantity of energy that can be lost or gained by an atom (plural: quanta) A
quantum is the minimum amount of any physical entity involved in an interaction.
continuous spectrum (94) the emission of a continuous range of frequencies of electromagnetic radiation
excited state (94) state in which an atom has a higher potential energy than it has in its ground state
ground state (94) The lowest energy state of an atom
line-emission spectrum (94) When a narrow beam of the emitted light was shined through a prism, it is
separated into a series of specific frequencies(and therefore specific wavelengths, λ = c/f) of visible
light. The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies
of electromagnetic radiation emitted due to an atom's electrons making a transition from a high energy
state to a lower energy state. The energy of the emitted photon is equal to the energy difference between
the two states. There are many possible electron transitions for each atom, and each transition has a
specific energy difference. These collections of different transitions, leading to different radiated
wavelengths, make up an emission spectrum. Each element's emission spectrum is unique. Therefore,
spectroscopy can be used to identify the elements in matter of unknown composition. Similarly, the
emission spectra of molecules can be used in chemical analysis of substances.
photon (94) a particle of electromagnetic radiation having zero mass and carrying a quantum of energy.
Heisenberg uncertainty principle (99) it is impossible to determine simultaneously both the position and
velocity of an electron or any other quantum particle.
quantum theory (99) describes mathematically the wave properties of electrons and other very small
particles
orbital (100) the three-dimensional region around the nucleus of the probable location of an electron
quantum number (101) specify the properties of atomic orbitals and the properties of electrons in
orbitals
principal quantum number (101) symbolized by n, indicates the main energy level occupied by the
electron n must be a counting number an electron for which n = 1 occupies the first, or lowest, main
energy level and is located closest to the nucleus. n=2 is next and so on
angular momentum quantum number (101) symbolized by l, indicates the shape of the orbital; different
shapes; known as sublevels; exist for each given value of n. Values of l allowed are zero and all positive
integers less than or equal to n – 1: A.K.A. azimuthal quantum number
magnetic quantum number (102) symbolized by m, indicates the orientation of an orbital around the
nucleus (m < |l|  – l < m < l)
spin quantum numbers (104) indicates which of the two fundamental spin states of an electron has in an
orbital There are only two possible values (+½ , − ½)
Aufbau principle (105) an electron occupies the lowest-energy orbital that can receive it
electron configuration (105) arrangement of electrons in an atom in atomic or molecular orbitals
Pauli exclusion principle (106) no two electrons in the same atom can have the same set of four quantum
numbers
Hund’s rule (106) orbitals of equal energy are each occupied by one electron before any orbital is
occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin
highest occupied level (110) the electron-containing main energy level with the highest principal
quantum number (AKA the highest shell)
inner-shell electrons (110) electrons that are not in the highest occupied energy level
noble gases (111) The Group 18 elements (helium, neon, argon, krypton, xenon, and radon)
noble-gas configuration (112) is an outer main energy level fully occupied, in most cases, by eight
electrons