Electronic Structure and Periodic Properties of Elements Ch 3- Key Terms

Actinide

Inner transition metal in the bottom of the bottom two rows of the periodic table

Alkali Metal

Element in group 1

Alkaline Earth Metal

Element in group 2

Amplitude

Extent of the displacement caused by a wave

Atomic Orbital

Mathematical function that describes the behavior of an electron in an atom (also called the wave function)

Aufbau Principle

Procedure in which the electron configuration of the elements is determined by “building” them in order of atomic numbers, adding one proton to the nucleus and one electron to the proper subshell at a time

Black body

idealized perfect absorber of all incident electromagnetic radiation; such bodies emit electromagnetic radiation

Bohr’s Model of the Hydrogen Atom

Structural Model in which an electron moves around the nucleus only in circular orbits, each with a specific allowed radius

Chalcogen

Element in group 16

Continuous Spectrum

Electromagnetic radiation given off in an unbroken series of wavelength (e.g., white light from the sun)

Core Electron

Electron in an atom that occupies the orbitals of the inner shells

Covalent Bond

Attractive force between the nuclei of a molecules atom and pairs of electrons between the atoms

Covalent Compound

Composed of molecules formed by atoms of two or more different elements

Covalent Radius

One-half the distance between the nuclei of two identical atoms when they are joined by a covalent bond

d Orbital

Region of space with high electron density that is either four lobed or contains a dumbbell and torus shape; describes orbitals with / = 2

Degenerate Orbitals

Orbitals that have the same energy

Effective Nuclear Charge

Charge that leads to the Coulomb force exerted by the nucleus on an electron, calculated as the nuclear charge minus shielding

Electromagnetic Radiation

Energy transmitted by waves that have an electric field component and a magnetic field component

Electromagnetic Spectrum

Range of energies that electromagnetic radiation can comprise, including radio, microwaves, infrared, visible, ultraviolet, X-rays, and gamma rays

Electron Affinity

Energy change associated with addition of an electron to a gaseous atom or ion

Electron Configuration

Listing that identifies the electron occupancy of an atoms shells and sub shells

Electron Density

A measure of the probability of locating an electron in a particular region of space, it is equal to the squared absolute value of the wave function ψ

Endothermic

Processes that increase the energy of an atom and involve the absorption of light

Excited State

State having an energy greater than the ground-state energy

Exothermic

Processes that decrease the energy of an atom and involve the emission of light

f Orbital

Multilobed region of space with high electron density, describes orbitals with l = 3

Frequency (ν)

Number of wave cycles (peaks or troughs) that pass a specified point in space per unit time

Ground state

State in which the electrons in an atom, ion, or molecule have the lowest energy possible

Group

vertical column of the periodic table

Halogen

Element in group 17