Chem Midterm - Chapter 5 Vocabulary

Electromagnetic Radiation

Electromagnetic Radiation

A form of energy that exhibits wavelike behavior as it travels through space

Wavelength (λ)

the shortest distance between equivalent points on a continuous wave

Frequency (v)

The number of waves that pass a given point per second

Amplitude

A wave’s height from the origin to a crest, or from the origin to a trough

Electromagnetic Spectrum (EM Spectrum)

Includes all forms of electromagnetic radiation, with the only differences in the types of radiation being their frequencies and wavelengths

Quantum

The minimum amount of energy that can be gained or lost by an atom

Photoelectric Effect

When electrons (called photoelectrons) are emitted from a metal’s surface when light of a certain frequency or higher, shines on the surface

Photon

A massless particle that carries a quantum of energy

Atomic Emission Spectrum

The set of frequencies of the electromagnetic waves emitted by atoms of the element

Ground State

The lowest acceptable energy state of an atom

Quantum Mechanical Model of Atom

The atomic model in which electrons are treated as waves

Atomic Orbital

A 3D region around the nucleus, which describes the electron’s probable location

Principal Quantum Number (n)

Indicates the relative size and energy of atomic orbitals

Principal Energy Level

Each major energy level

Energy Sublevel

Are part of principal energy levels

Electron Configuration

the arrangement of electrons in an atom

Aufbau Principle

Each electron occupies the lowest energy orbital available

Hund’s Rule

Single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbital

Valence Electron

Electrons in the atom’s outermost orbital

Electron (Lewis) Dot Structure

A model that consists of the element’s symbol surrounded by dots representing all of the atom’s valence electrons