Atomic Theory

Atomic Theory

Democritus
Made a mental model of the atom, greek philiosopher
Rutherford
Discovered the nucleus using his gold foil experiment
Wave Model
Current model of the atom, proposed by schrodinger
Electron
the negative particle that circles the nucleus
Dalton
Formed the atomic theory model of the atom, english school teacher
Proton
The positive particle in the nucleus of an atom
Neutron
The neutral particle in the nucleus of an atom
Model
used by scientists to explain something we can not see or understand
Thompson
Proposed the plum pudding model of the atom, discovered electrons
Atom
the smallest particle of an element that has the properties of that element
Nucleus
the tiny positive core of an atom, contains protons and nuetrons
Energy Levels
the paths in which electrons circle the nucleus of an atom
Chadwick
discovered the neutron
Bohr
developed the model of the atom in which electrons orbit the nucleus in energy levels
Alpha particle
used by rutherford in his experiment, made of two protons and two neutrons
Electron Cloud
current explanation of where electrons might be found in the atom
allotrope
Different forms of the same element
anion
A negatively charged ion
atom
Smallest part of an element
atomic mass
The average mass of all the naturally ocurring isotopes of an element
atomic mass unit
a unit of mass that describes the mass of an atom or molecule
bohr model
model of an atom that shows electrons in circular orbits around the nucleus
cation
A positively charged ion
compound
A substance made up of atoms of two or more different elements joined by chemical bonds
electron
A subatomic particle that has a negative charge
electron configuration
the arrangement of electrons in an atom
element
A pure substance made of only one kind of atom
excited state
A state in which an atom has a higher potential energy than it has in its ground state
ground state
The lowest energy state of an atom
ion
A charged atom
isotopes
Atoms of the same element that have different numbers of neutrons.
kernel electrons
inner electrons
lewis dot diagram
A method for representing an atom’s valence electrons using dots around the element symbol.
mass number
the sum of the number of neutrons and protons in an atomic nucleus
neutron
A subatomic particle that has no charge and that is found in the nucleus of an atom
nuclear charge
the electric charge on an atom’s nucleus, which can be determined by counting the number of protons
nucleus
makes up pretty much all the mass in the atom therefore mass number equals number of protons plus the number of neutrons
nucleons
A particle in an atomic nucleus, either neutron or a proton
orbit
A circular path
orbital
A region of space around the nucleus where an electron is likely to be found.
proton
A subatomic particle that has a positive charge and that is found in the nucleus of an atom
quantum theory
The theory that describes matter and energy at very small (atomic) sizes.
valence electrons
Electrons on the outermost energy level of an atom
wave mechanical model
electrons have distinct amounts of energy and move in areas called orbitals
gold foil experiment
This was Ernst Rutherford’s experiment that led to the discovery of the nucleus as the small, dense, positively charged center of the atom and the development of the nuclear theory of the atom.
nucleons
subatomic particles found in the nucleus
who preformed the cathode ray experiment
J.J Thomson
what subatomic particle was found during the cathode ray experiment
electron
ground state vs excited state
Electrons in lowest energy level vs electrons in highest energy level
valence electrons
electrons on the outer shell
energy can have both what
waves and particles
Orbit
set paths that electrons take around nucleus according to planetary/bohr model