Chem Vocab Ch. 5

Energy Levels

Fixed energies an electron can have

Quantum

Amount of energy requires to move an electron from one energy level to another energy level.

Quantum Mechanical Model

Modern description of the electrons in atoms.

Atomic Orbital

describes the probability of finding an electron at various locations around the nucleus.

Electron Configuration

The ways in which electrons are arranged in various orbitals around the nuclei of atoms.

Aufbau Principle

states that electrons can occupy the orbitals of lowest energy first.

Pauli Exclusion Principle

states that an atomic orbital may describe at most two electrons.

Spin

a quantum mechanical property of electrons and may be thought of as clockwise or counterclockwise.

Hund's rule

Electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible.

Amplitude

wave's height from zero to the crest

Wavelength

is the distance between the crests.

Frequency

number of wave cycles to pass a given point per unit of time.

Hertz

the SI unit of cycles per second

Electromagnetic radiation

includes radio waves, microwaves, infrared waves, etc.

Spectrum

Wavelengths of visible light that are separated when a beam of light passes through a prism; range of wavelengths of electromagnetic radiation

Atomic emission spectrum

Pattern formed when light passes through a prism or diffraction grating to separate it into the different frequencies of light it contains.

Photoelectric effect

states that electrons are ejected when light shines on a metal. Not just any light will cause the photoelectric effect.

photons

light quanta.

ground state

when the electron is in the lowest possible energy

Heisenberg uncertainty principle

states that it is impossible to know both velocity and the position of a particle at the same time.