Atomic Theory Flashcards

Flashcards covering atomic theory, structure, electron configurations, and related concepts.

Isotopes

Atoms of the same element with different numbers of neutrons. they have the same number of protons

Mass spectrometry

Used to determine the relative atomic masses of elements from their isotopic composition.

Emission spectra

Produced by atoms emitting photons when electrons in excited states return to lower energy levels.

Line emission spectrum of hydrogen

Evidence for the existence of electrons in discrete energy levels, which converge at higher energies.

Sublevels

The division of the main energy level into s, p, d, and f sublevels of successively higher energies.

Ionization energy (IE)

Refers to the energy required to remove an electron from a gaseous atom or ion.

Atomic Theory

All matter is described as a number of small, indivisible, and indestructible particles called atoms

Atomic number (Z)

Equal to the number of protons in the nucleus.

Mass number (A)

Equal to the total number of protons and neutrons.

Atomic mass unit (amu)

The standard unit for indicating mass on an atomic scale, defined as one-twelfth of the mass of a neutral atom of carbon-12.

Absorption Spectrum

absorbed as atoms (electrons) move from a lower to a higher energy level.

Emission spectrum

atoms (electrons) return to lower energy levels from higher energy levels.

Aufbau Principle

Electrons fill the lowest available energy level before filling higher energy levels

Pauli Exclusion Principle

Each orbital can hold two electrons; they must have opposite spins.

Hund's Rule

Every orbital in a sublevel must be singly occupied by electrons with the same spin before any orbital is doubly occupied.

Isoelectronic

Species with the same electron configuration ex. He, H-, Li+

visible region on line spectra

balmer series of hydrogen corresponding to transitions of electrons from higher energy levels to level 2.