How can we help?

You can also find more resources in our Help Center.

37 terms

The Atom: Unit 3.1

the smallest part of an element that retains the properties of that element
atomic theory
an explanation of the behavior of matter in terms of tiny particles called atoms
the positively charged particle in the nucleus of an atom
the neutral particle in the nucleus of an atom
the negatively charged particle in an atom, located in orbitals
regions of high probability of finding electrons, electron clouds
well-defined areas where electrons definitely are
the center of the atom, contains protons and neutrons
atomic mass unit, used to measure the mass of atoms and subatomic particles
atomic number
equal to the number of protons in an atom, defines the atom as a certain element
mass number
equal to the number of protons plus the number of neutrons, identifies a specific isotope of an element
an atom of a certain element that varies in its number of neutrons
atomic mass
the weighted average of the masses of all isotopes of an element
an atom that has gained or lost electrons and therefore has a charge
a positive ion, an atom that has lost one or more electrons
a negative ion, an atom that has gained one or more electrons
polyatomic ions
groups of 2 or more covalently bonded atoms that have an overall charge
stable octet
a group of 8 valence electrons, very stable, the goal for ion formation and most bonding
nuclide symbol
a representation of an atom or ion that shows the element symbol, atomic number, mass number, and charge (if present)
principle energy level
a collection of orbitals grouped together based on their common energies
electron configuration
the specific arrangement of electrons in an atom or ion
valence electrons
the electrons in the highest principle energy level
oxidation states
the charges of the most common ions of an element
Lewis dot structure
used to represent valence electron arrangement in an atom or ion
ground state
the energy level that an electron normally occupies, a lower energy state
excited state
a higher energy level that an electron can enter if it absorbs the right amount of energy
a specific amount of energy, electrons can absorb this to enter a higher energy state
bright line spectra
the unique amounts of energy emitted as electrons return to the ground state, specific colors shown as individual bright lines
continous spectrum
the entire ROY G BIV color spectrum
plum pudding model
the model of the model of the atom created by JJ Thomson, consists of electrons on the surface of a positively charged sphere
solar system model
the model of the atom created by Bohr, consists of electrons orbiting the central nucleus
gold foil experiment
an experiment done by Rutherford, proved that atoms are mostly empty space and have a dense, positive nucleus
cathode ray tube experiment
experiment done by Thomson in which he discovered the electron
cannon ball model
the model of the atom created by Dalton, states that atoms are solid spheres with no internal structure
Wave-Mechanical model
the model of the atom created by Schrodinger, states that electrons are in orbitals around the central nucleus, sometimes called the electron cloud model
dual nature of the electron
states that electrons behave as both pure energy and as particles