Understanding Atomic Structure and Electron Configuration

These flashcards cover key vocabulary and concepts related to atomic structure and electron configuration, highlighting important terms, their definitions, and fundamental principles.

Atom

The basic unit of matter, consisting of a nucleus surrounded by electrons.

Nucleus

The central part of an atom containing protons and neutrons.

Proton

A positively charged particle found in the nucleus of an atom.

Neutron

A neutral particle found in the nucleus of an atom.

Electron

A negatively charged particle that orbits the nucleus of an atom.

Shell

A region around the nucleus where electrons are likely to be found.

Quantum Number

A number that describes the energy levels and location of electrons in an atom.

Shell Number (n)

The principal quantum number that indicates the main energy level of an electron.

Subshell (l)

A division of electron shells; indicated by the azimuthal quantum number and can have values from 0 to n-1.

Azimuthal Quantum Number

Another name for the subshell number (l), describing the shape of the electron's orbital.

s subshell

The subshell where l = 0; can hold a maximum of 2 electrons.

p subshell

The subshell where l = 1; can hold a maximum of 6 electrons.

d subshell

The subshell where l = 2; can hold a maximum of 10 electrons.

Spin quantum number (ms)

A quantum number representing the two possible spin states of an electron: +1/2 (spin up) and -1/2 (spin down).

Aufbau Principle

The principle stating that electrons occupy the lowest energy orbitals first.

Pauli Exclusion Principle

A principle stating that no two electrons can have the same set of four quantum numbers.

Hund's Rule

A rule stating that electrons will occupy degenerate orbitals singly before pairing up in the same orbital.

Electron Configuration

A notation that shows the distribution of electrons in an atom's orbitals.

Inert Gases

Elements in Group 18 of the periodic table that have full outer electron shells and are mostly unreactive.

Atomic Number

The number of protons in the nucleus of an atom, which determines the element.