Atomic Theory Definitions Chapter 3 Flashcards
A positively charged subatomic particle found in the nucleus of atoms
Proton
A variety of atoms of an element, Atoms of this variety have the same number of protons as all atoms of the element, but a different number of neutrons
Isotope
A neutral(unchanged) subatomic particle present in the nucleus of atoms
Neutron
the release of electrons from a substance due to light striking the surface of a metal
Photoelectric Effect
A small discrete, invisible quantity(Plural quanta); A quantum of light is a photon; a burst of some energy
Quantum
A quantum of light energy, A stream of energy packets(quanta)
Photon
A technique for analyzing spectra; the spectra may be visible light, infrared, ultraviolet, x-ray, and other types
Spectroscopy
A series of bright lines of light produced or emitted by a gas excited by heat or electricity
Bright-Line/Emission Spectrum
A series of dark lines of a continuous spectrum; is produced by placing a gas between the continuous spectrum source and the observer; also known as a dark line spectrum
Absorption Spectrum
A stable energy state of an atomic system that does not involve any emission of radiation
Stationary State
The jump of an electron from one stationary state to another
Transition
Electrons do not radiate energy while orbiting the nucleus
Bhor’s First Postulate
Electrons can change energy by undergoing a transition from one stationary state to another
Bhor’s Second Postulate
A region of space around a nucleus where an electron is most likely to be found
Orbital
Main energy level, number n(quantum numbers), corresponds to the periodic table for s and p groups
Shell
Orbitals of different shapes and energies, given by the quantum number
Subshell
when electrons are added to an atom, they go into the lowest energy available and fill the levels in order of increasing energy level until electrons run out
Aufbau Principle
No two electrons in an atom can have the same 4 numbers(quantum); no two electrons in the same orbital have the same spin; only two electrons with opposite spins can occupy an orbital
Pauli Exclusion Principle
states that one electron occupies each of several orbitals at the same energy level before a second electron can occupy the same orbital
Hund’s Rule
A method for communicating the location and number of electrons in electron energy levels
Electron Configuration
The metals and non-metals in the main blocks, S and P blocks
Representative Elements
The metals in groups 3-12; elements filling d-orbitals with electrons
Transition Elements
The 14 metals in each of periods 6 and 7 that range in atomic numbers 57-70 and 89-102 respectively; elements filling f-block
Lanthanides and Actinides
It is impossible to simultaneously know the exact position and speed of a particle
Heisenberg Uncertainty Principle
The current theory of atomic structure based on wave properties of electrons; Also known as wave mechanics
Quantum Mechanics
A mathematical or graphical representation of the chance of finding an electron in a given space
Electron Probability Density
Created the plum pudding model aka the Raison Bun model, atoms make up of electrons scattered unevenly within an elastic sphere surrounded by a soup of positive charges to balance the electron’s charge
J J Thomson
Performed the gold foil experiment to discover a positively charged nucleus, and concluded that the atom’s nucleus consists of positively charged subatomic particles, called protons. Used alpha particles in the experiment.
Ernest Rutherford
introduced the idea that particles such as electrons could be also described as waves. “If a wave can behave like a particle, then a particle can behave as a wave.”
De Brogile
hypothesized that energies from oscillating atoms in the heated object were multiples of a small quantity of energy. The light was emitted in bursts of energy in waves rather than as a continuous stream
Planck
Electrons can change(gain or lose energy) their energy by undergoing a transition from one transition state to another
Bhor
the electron can only have certain(quantized) energies because of the requirements for only whole numbers of wavelengths of the electron. Suggested the energy of hydrogen electrons was quantized because of its specific orbit. Therefore since electron energy has certain values, changes in energy also have certain values.
Schrodinger
-Weak attraction to magnetic fields
-Unable to retain magnetic properties when a field is removed
-Domains are randomly oriented
-Examples: Oxygen, Lithium, Chlorine…
Paramagnetisim
-Strong attraction to magnetic fields
-Able to retain magnetic properties when a field is removed
-Domains are lined up creating a “permanent magnet”
-Examples: Iron, Cobalt, Nickel
Ferromagnetism
Anything under Copper and Chromium, Has half-filled shells for example copper has 4s1 and chromium has 4s1. The other electron is promoted to the 3d orbital
Anomalus
