Periodic Table and Quantum Mechanics Concepts

These flashcards cover key vocabulary and concepts related to periodicity, atomic structure, and quantum mechanics from the lecture notes.

Periodicity

A repetitive pattern of properties displayed by the elements in the periodic table.

Atomic Size

A measure of the size of an atom, which shows periodic behavior across a period and down a group.

Electromagnetic Radiation

A type of energy that can display a wave-like nature, including wavelengths and frequencies.

Wavelength (λ)

The distance between crests of a wave, measured in units of length.

Frequency (ν)

The number of crests that pass a given point per second, measured in Hertz (Hz).

Planck’s Constant (h)

A physical constant used to describe the size of quanta in quantum mechanics, valued at 6.626 x 10^-34 J·s.

Heisenberg Uncertainty Principle

The principle stating that the more exactly we know the velocity of an electron, the less exactly we can know its position.

Quantum Numbers

A set of values (n, l, ml, ms) that describe the energy, shape, and orientation of orbitals in an atom.

Valence Electrons

The electrons in the outermost shell of an atom, which are involved in chemical reactions.

Ground State

The lowest energy state of an atom, where electrons are in their most stable configuration.

Hund's Rule

When placing electrons in orbitals of the same energy, place them in separate orbitals first, with parallel spins.

Node

An area of zero electron density within an orbital where an electron is never found.

Orbital Types

Different types of orbitals (s, p, d, f) that describe the shape and orientation of electron clouds.

S orbital

A spherical-shaped orbital that can hold a maximum of two electrons.

P orbital

A dumbbell-shaped orbital that can hold a maximum of six electrons across three orientations.

D orbital

A more complex shaped orbital that can hold a maximum of ten electrons.

Electron Configuration

The notation used to describe the distribution of electrons among the orbitals of an atom.

Shorthand Notation

A condensed way to write electron configurations using the nearest noble gas.

Special Stability

The increased stability associated with half-filled or fully filled d orbital subshells.