CHEM 10060 Module 4 - Electronic Structure of Atoms Vocabulary

Vocabulary flashcards covering quantum theory, electron configurations, atomic orbitals, and periodic trends from CHEM 10060 General Chemistry 1 - Module 4.

Frequency ($\nu$)

The number of wave cycles per second, expressed in units of hertz ($Hz = s^{-1}$).

Wavelength ($\lambda$)

The distance a wave travels in one complete cycle, typically expressed in nanometers ($nm = 10^{-9}\,m$).

Speed of Light ($c$)

The distance light moves per unit time, which is a constant equal to $3.00 \times 10^8\,m/s$ in a vacuum.

Amplitude

The height of a wave crest or depth of a wave trough.

Quantum

The smallest discrete quantity of a particular form of energy.

Photon

A quantum of electromagnetic radiation.

Planck's Constant ($h$)

A fundamental constant relating radiant energy to frequency, equal to $6.626 \times 10^{-34}\,J \cdot s$.

Atomic Absorption Spectrum

A characteristic series of dark lines produced when free, gaseous atoms are illuminated by a continuous source of radiation.

Atomic Emission Spectrum

A characteristic series of bright lines produced by excited atoms emitting light.

Ground State

The lowest-energy level available to an electron in an atom ($n = 1$).

Excited State

Any energy state of an electron in an atom above its ground state.

Ionization

The complete removal of an electron from an atom, occurring when $n = \infty$.

Heisenberg Uncertainty Principle

Principle stating that both the position ($x$) and momentum ($mv$) of an electron in an atom cannot be determined simultaneously.

Wave Function ($\Psi$)

A mathematical function describing the motion of electron waves as they vary with location and time.

Principal Quantum Number ($n$)

A quantum number indicating the electron shell and relative size of the orbital(s), represented by integers $n = 1, 2, 3 \dots$.

Angular Momentum Quantum Number ($\ell$)

A quantum number defining the shape of an orbital and subshell, taking integer values from $0$ to $(n - 1)$.

Magnetic Quantum Number ($m_\ell$)

A quantum number defining the orientation of an orbital in 3D space around the nucleus, taking integer values from $-\ell$ to $+\ell$.

Spin Quantum Number ($m_s$)

A quantum number describing the property of electron spin, taking values of $+\frac{1}{2}$ or $-\frac{1}{2}$.

Pauli Exclusion Principle

Principle stating that no two electrons in an atom can have the same set of four quantum numbers.

Effective Nuclear Charge ($Z_{\text{eff}}$)

The net nuclear charge an electron actually experiences after accounting for shielding by other electrons.

Aufbau Principle

The method of building electron configurations by filling the lowest-energy available orbitals first as atomic number increases.

Hund's Rule

Rule stating that for degenerate orbitals of equal energy, the lowest-energy configuration has the maximum number of unpaired electrons.

Inner (Core) Electrons

Electrons an atom has in common with the previous noble gas and any completed transition series.

Outer Electrons

Electrons residing in the highest energy level (highest principal quantum number $n$) of an atom.

Valence Electrons

Electrons involved in forming chemical compounds; equal to outer electrons for main-group elements.

Metallic Radius

Half the shortest distance between nuclei of adjacent, individual atoms in a crystal of a metal.

Covalent Radius

Half the shortest distance between nuclei of identical, covalently bonded atoms.

Ionization Energy (IE)

The amount of energy required to remove $1\,mol$ of electrons from $1\,mol$ of ground-state gaseous atoms or ions.

Electron Affinity (EA)

The energy change associated with adding $1\,mol$ of electrons to $1\,mol$ of atoms or ions in the gas phase.

Isoelectronic Series

A series of ions and/or atoms that possess the exact same electron configuration.

Diamagnetic Substance

A substance with no unpaired electrons whose apparent mass is unaffected by a magnetic field.

Paramagnetic Substance

A substance containing one or more unpaired electrons that is attracted by a magnetic field.