Chapter 4 chemistry
Planck's constant
6.626 x10 ^-34 Jxs where J is this symbol for the joule
Electromagnetic radiation
A form of energy that exhibits wavelike behavior as it travels through space
Beta particle
A high-speed electron with a 1- charge that is emitted during radioactive decay
Electron
A negatively charged, fast-moving particle with an extremely small mass that is found in all forms of matter and moves through the empty space surrounding an atom's nucleus
Neutron
A neutral, subatomic particle in an atom's nucleus that has a mass nearly equal to that of a proton
Alpha particle
A particle with two protons and two neutrons, with a 2+ charge; is equivalent to a helium-4 nucleus; and is emitted during radioactive decay
Nuclear reaction
A reaction that involves a change in the nucleus of an atom
Radioactive decay
A spontaneous process in which unstable nuclei lose energy by emitting radiation
Nuclear equation
A type of equation that shows the atomic number and mass number of the particles involved
Principal quantum number (n)
Assigned by the quantum mechanical model to indicate the relative sizes and energies of atomic orbitals
Isotope
Atom's of the same element with different numbers of neutrons
Quantum number
Bohr assigned a number , n
Principal energy level
Each major energy level
Valence electrons
Electrons in the atom's outermost orbitals- generally those orbitals associated with the atom's highest principal energy level
Beta radiation
Radiation that is made of beta particles
Gamma ray
High-energy radiation that has no electrical charge and no mass, is not deflected by electric or magnetic fields, usually accompanies alpha and beta radiation, and accounts for most of the energy lost during radioactive decay
Electromagnetic spectrum
Includes all forms of electromagnetic radiation, with the only differences in the types of radiation being their frequencies and wavelength
Photon
Massless particle that carries a quantum of energy
Radioactivity
The process in which some substances spontaneously emit radiation
Atomic mass unit
One-twelfth the mass of the isotopes of that element
De broglie equation
Predicts that all moving particles have wave characteristics
Energy sublevels
Principal energy levels contain
Alpha radiation
Radiation that is made up of alpha particles;is defected toward a negatively charged plate when radiation from a radioactive source is directed between two electrically charged plates
Cathode ray
Radiation that originates from cathode and travels to the anode of a cathode-Ray tube
Pauli exclusion principle
States that a maximum of two electrons can occupy a single orbital, but only if the electrons have opposite spins
Aufbau principle
States that each electron occupies the lowest energy orbital available
Dalton's atomic theory
States that matter is composed of extremely small particles called atoms
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
Proton
Subatomic particle in an atom's nucleus that has a positive charge of 1+
Heisenberg uncertainty principle
That it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time
Radiation
The Rays and particles- alpha and beta particles and gamma rays-that are emitted by radioactive materials
Electron configuration
The arrangement of electrons in an atom
Quantum mechanical model of the atoms
The atomic model in which electrons are treated s waves
Electron-dot structure
The elements symbol, which represents the atomic nucleus and inner-level electrons, surrounded by dots representing all of the atom's valence electrons
Nucleus
The extremely small, positively charged, dense center of an atom that contains positively charged protons and neutral neutrons
Ground state
The lowest allowable energy state of an atom
Quantum
The minimum amount of energy that can be gained or lost by an atom
Mass number
The number after an elements name, representing the sum of its proton and neutrons
Frequency
The number of aves that pass a given point per second
Atomic number
The number of protons in an atom
Atomic emission
The set of frequencies of the electromagnetic waves emitted by atom's of the element
Wavelength
The shortest distance between equivalent points on a continuous wave
Atom
The smallest particle of an element that retains all the properties of that element
Atomic orbitals
The wave function predicts a three-dimensional region around the nucleus
Photoelectric effect
The wave model of light could not explain a phenomemon
Amplitude
The waves height from the origin to a crest or from the origin to a trough
Atomic mass
The weighted average mass of the isotopes of that element