Chapter 5: Periodic Properties of the Elements Flashcards
alkali metals
Highly reactive metals in group 1A of the periodic table.
alkaline earth metals
Fairly reactive metals in group 2A of the periodic table.
aufbau principle
The principle that indicates the pattern of orbital fillingin an atom.
atomic radius
A set of averge bonding radii determined from measurements on a large number of elements and compounds.
Coulomb’s law
The law that states that the potential energy (E) of two charged particles depends on their charges (q1 and q2) and on their separation (r): E = (1/(4πε0))/((q1q2)/r)
core electrons
Those electrons in a complete principal energy level and those in complete d and f sublevels.
covalent radius (bonding atomic radius)
In nonmetals, one-half the distance between two atoms bonded together, and in metals, one-half the distance between two adjacent atoms in a crystal of the metal.
degenerate
Describes two or more electron orbitals with the same value of n that have the same energy.
effective nuclear charge (Zeff)
The actual nuclear charge experienced by an electron, defined as the charge of the nucleus plus the charge of the shielding electrons.
diamagnetic
The state of an atom or ion that contains only paired electrons and is, therefore, slightly repelled by an external magnetic field.
electron affinity
The energy change associated with the gaining of an electron by an atom in its gaseous state.
electron configuration
A notation that shows the particular orbitals that are occupied by electrons in an atom.
family (or group) of elements
One of the columns within the main group elements in the periodic table that contain elements that exhibit similar chemical properties.
ground state
The lowest energy state of an atom or molecule.
halogens
One of the highly reactive nonmetals in group 7A of the periodic table.
ionization energy
The energy required to remove an electron from an atom or ion in its gaseous state.
main-group elements
One of the elements found in the s or p blocks of the periodic table, whose properties tend to be predictable based on their position in the table.
metalloids
A member of a category of elements found on the boundary between the metals and nonmetals of the periodic table, with properties intermediate between those of both groups; metalloids are also called semimetals.
noble gases
One of the group 8A elements, which are largely unreactive (inert) due to their stable filled p orbitals.
nonmetals
A member of a class of elements that tend to be poor conductors of heat and electricity and usually gain electrons during chemical reactions.
Hund’s rule
The principle stating that when electrons fill degenerate orbitals, they first fill them singly with parellel spins.
orbital diagram
A diagram that gives information similar to an electron configuration but symbolizes an electron as an arrow in a box representing an orbital, with the arrow’s direction denoting the electron’s spin.
paramagnetic
The state of an atom or ion that contains unpaired electrons and is, therefore, attracted by an external magnetic field.
Pauli exclusion principle
The principle that no two electrons in an atom can have the same four quantum numbers.
penetration
The phenomenon of some higher-lever atomic orbitals having significant amounts of probability within the space occupied by orbitals of lower energy level. For example, the 2s orbital penetrates into the 1s orbital.
periodic law
A law based on the observation that when the elements are arranged in order of increasing mass, certain sets of properties recur periodically.
metals
A member of large class of elements that are generally good conductors of heat and electricity, are malleable, ductile, and lustrous, and tend to lose electrons during chemical changes.
periodic property
A property of an element that is predictable based on an element’s position in the periodic table.
semiconductors
A material with intermediate electrical conductivity that can be changed and controlled.
shielding
The effect on an electron of repulsion by electrons in lower-energry orbitals that screen it from the full effects of nuclear charge.
transition elements (or transition metals)
One of the elements found in the d block of the periodic table whose properties tend to be less predictable based simply on their position in the table.
valence electrons
The electrons that are important in chemical bonding. For main-group elements, the valence electrons are those in the outermost principal energy level.
van der Waals radius (nonbonding atomic radius)
One-half the distance between the centers of adjacent, nonbonding atoms in a crystal.
