# Chapter 5 Vocab

## 24 terms

A form of energy exhibiting wavelike behavior as it travels through space; can be described by wavelength, frequency, amplitude, and speed. Includes visible light, microwaves, X rays, and radio waves.

### Wavelength

The shortest distance between equivalent points on a continuous wave. Represented by λ, the Greek letter lambda.

### Frequency

The number of waves that pass a given point per second. Unit of frequency is the Hertz (Hz) or waves per second (1/s).

### Amplitude

The wave's height from the origin to the crest or from the origin to the through.

### Electromagnetic Spectrum

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

### Quantum

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

### Planck's Constant

In energy equation E=hv, h. Value of 6.626x10^-34J*s.

### Photoelectric Effect

When photoelectrons are emitted from a metal
surface when light of a certain frequency shines on the surface.

### Photon

A particle of electromagnetic radiation with no mass that carries a quantum of energy.

### Atomic Emission Spectrum

A set of frequencies of the electromagnetic waves emitted by atoms of the element.

### Ground State

The lowest allowable energy state of an atom.

### de Broglie Equation

An equation that predicts that all moving particles have wave characteristics and relates each particle's wavelength to its frequency, mass, and Planck's Constant.

### Heisenberg Uncertainty Principle

States that it is not possible to know precisely both the velocity and position of a particle at the same time.

### Quantum Mechanical Model of the Atom

An atomic model in which electrons are treated as waves; also called the wave mechanical model of the atom.

### Atomic Orbital

A 3D region around the nucleus of an atom that describes an electron's probable location.

### Principal Quantum Number

n, which the quantum mechanical model assigns to indicate the relative sizes and energies of the atoms.

### Principal Energy Level

The major energy levels of an atom.

### Energy Sublevel

The energy levels contained within a principal energy level.

### Electron Configuration

The arrangement of electrons in an atom, which is prescribed by three rules - the aufbau principle, the Pauli exclusion principle, and Hund's rule.

### Aufbau Principle

States that each electron occupies the lowest energy orbital; available.

### Pauli Exclusion Principle

States that a maximum of two electrons may occupy a single atomic orbital, but only if the electrons have opposite spins.

### Hund's Rule

States that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals.

### Valance Electron

The electrons in an atom's outermost orbitals; determine the chemical properties of an element.

### Electron-Dot Structure

Consists of an element's symbol, representing the atomic nucleus and inner-level electrons, that is surrounded by dots, representing the atom's valance electrons.