Waves and Particles
Light has characteristics of these two things.
Electromagnetic Radiation
A form of energy that exhibits wavelike behavior as it travels through space.
Electromagnetic Spectrum
All the forms of electromagnetic radiation.
Same
Do the forms of electromagnetic radiation move at the same speed or a different speed through a vacuum?
Wavelength
The distance between corresponding points on adjacent waves.
Frequency
The number of waves that pass a given point in a specific time, usually one second.
Hertz
Unit used to express frequency.
Inversely Proportional
Wavelength and Frequency are _____________ ____________.
Photoelectric Effect
Refers to the emission of electrons from a metal when light shines on the metal.
Frequency
Lightâs ____________ needs to reach a certain minimum in order to emit electrons from a certain metal.
Max Planck
German physicist who explained the photoelectric effect after studying the emission of electrons by hot objects.
Quantum
The minimum quantity of energy that can be lost or gained from an atom.
Albert Einstein
German physicist who suggested that electromagnetic radiation had a dual wave-particle nature, and that it is absorbed by matter in only whole numbers of photons.
Photon
Particle of electromagnetic radiation having zero mass and carrying a quantum of energy.
Ground State
The lowest energy state of an atom; only one for atoms of a given element.
Excited State
A state in which an atom has a higher potential energy than it has in its ground state; there are many possible, each with a unique energy.
Released
Energy is ___________ in the form of electromagnetic radiation when an atom returns to a ground state or a lower energy state from an excited state.
Emission-Line Spectrum
When a narrow beam of emitted light is shined through a prism, it is separated into specific colors of the visible spectrum; these bands of light make up an elementâs [this].
Continuous Spectrum
The emission of a continuous range of frequencies of electromagnetic radiation.
Quantum Theory
Atomic theory that attempted to explain why the hydrogen atoms only gave off specific frequencies of light.
Equal
The energy of the photon released is _________ to the difference in energy between the atomâs initial state and its final state.
Orbits
Paths that the electron can circle the nucleus on as part of Bohrâs model of the hydrogen atom.
Increases
The energy of an electron ___________ as it moves farther away from the nucleus.
Gaining
An electron can move to a higher-energy orbit by __________ an amount of energy equal to the difference in energy between the desired and initial orbit.
Emission
Process by which an electron falls to a lower energy level and releases a photon.
Absorption
Process by which energy is added to an atom in order to move an electron from a lower energy level to a higher energy level.
Louis de Broglie
Scientist who suggested that electrons have a dual wave-particle nature; suggested that electrons be considered waves confined to the space around an atomic nucleus.
Diffraction
The bending of a wave as it passes by the edge of an object or through a small opening.
Interference
Occurs when waves overlap, resulting in a reduction of energy in same areas and an increase in energy in others.
Heisenberg Uncertainty Principle
States that it is impossible to determine simultaneously both the position and velocity of an electron or any other particle.
Erwin Schrödinger
Used the hypothesis that electrons have a dual wave-particle nature to develop an equation that treated electrons in atoms as waves; quantization of electron energies was a natural outcome of said equation.
Quantum Theory
Describes mathematically the wave properties of electrons and other very small particles.
Wave Functions
Solutions to the Schrödinger wave equation.
Orbital
A three-dimensional region around the nucleus that indicates the probable location of an electron.
Quantum Numbers
Specify the properties of atomic orbitals and the properties of electrons in orbitals.
Principal Quantum Number
Symbolized by n, indicates the main energy level occupied by the electron. Values of n are positive integers only.
Increases
As n increases, the electronâs energy and its average distance from the nucleus ____________.
Angular Momentum Quantum Number
Symbolized by l, and indicates the shape of the orbital. The values of l allowed are 0 and all positive integers less than or equal to n-1.
S
Spherical orbitals; l=0.
P
Dumbbell-shaped orbitals; l=1.
D
Complex orbitals; l=2.
F
More complex orbitals; l=3.
N
In the nth main energy level, there are __ sublevels.
Magnetic Quantum Number
Symbolized by m, and indicates the orientation of an orbital around the nucleus. The m values are whole numbers (including 0) from -l to +l.
Spin Quantum Number
Has only two possible valuesâ+1/2 and -1/2âwhich indicate the two fundamental spin states of an electron in an orbital.
Electron Configuration
The arrangement of electrons in an atom.
Ground State Electron Configuration
The lowest-energy arrangement of the electrons for each element.
Aufbau Principle
An electron occupies the lowest-energy orbital that can receive it.
Pauli Exclusion Principle
No two electrons in the same atom can have the same set of four quantum numbers.
Hundâs Rule
Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin state.
Highest-Occupied Energy Level
The electron-containing main energy level with the highest principle quantum number
Inner-Shell Electrons
Electrons that are not in the highest-occupied energy level.
Octet
Atoms which have the s and p sublevels of their highest-occupied energy level are said to have an _______ of electrons.
Noble Gases
The elements in Group 18; includes Helium, Neon, Argon, Krypton, Xenon, and Radon
Noble Gas Configuration
Refers to an outer main energy level occupied, in most cases, by eight electrons.