Chapter 8 Flashcards
Periodic law
A law stating that when the elements are arranged by atomic number they exhibit a periodic recurrence of properties
electron configuration
The distribution of electrons within the orbitals of the atoms of an element; also the notation for such a distribution
spin quantum number(ms)
A number, either +1/2 or 1/2, that indicates the direction of electron spin
exclusion principle
A principle developed by Wolfgang Pauli stating that no two electrons in an atom can have the same set of four quantum numbers. The principle arises from the fact aha n orbital has a maximum occupancy of two electrons and their spins are paired
shielding
The ability of other electrons, especially those occupying inner orbitals, to lessen the nuclear attraction for an outer electron
effective nuclear charge(Zeff)
The nuclear charge an electron actually experiences as a result of shielding effects due to the presence of other electrons
penetration
The process by which an outer electron moves through the region occupied by the core electrons to spend part of its time closer to the nucleus; it increases the average effective nuclear charge for that electron
orbital diagram
A depiction of orbital occupancy in terms of electron number and spin shown by means of arrows in a series of small boxes, lines or circles
Hund’s rule
A principle stating that when orbitals of equal energy are available, the electron configuration of lowest energy has the maximum number of unpaired electrons with parallel spins
transition elements
An element with atomic number higher that that of uranium
inner(core) electrons
Electrons that fill all the energy levels of an atom except the valence level; electrons also present in atoms of the previous noble gas and any completed transition series
outer electrons
Electrons that occupy the highest energy level and are, on average, farthest from the nucleus.
valence electrons
The electrons involved in compound formation; in main-groups elements, the electrons in the valence level
inner transition elements
The elements of the periodic table in which f orbitals are being filled; the lanthanides and actinides
lanthanides
The period 6 series of inner transition elements, which includes cerium through lutetium
actinides
The period 7 elements that constitute the second inner transition series, which includes thorium through lawrencium
atomic size
One-half the distance between nuclei of two adjacent atoms in a sample of the element
metallic radius
One-half the shortest distance between the nuclei of adjacent individual atoms in a crystal of an element
covalent radius
One-half the shortest distance between nuclei of identical covalently bonded atoms
ionization energy
The energy required to remove completely one mole of electrons from one mole of gaseous atoms or ions
electron affinity
The energy change accompanying the addition of one mole of electrons to one mole of gaseous atoms or ions
amphoteric
Able to act as either an acid or a base
isoelectronic
Having the same number and configuration of electrons as another species
pseudo-noble gas configuration
The (n-1)d^10 configuration of a p-block metal ion that has an empty outer energy level
