Chapter 3 Test Flashcards
The atomic model developed by J. J. Thomson that views atoms as spheres of positively charged material with embedded electrons
Plum Pudding Model
The atomic model developed by Ernest Rutherford in which an atom is made up of tiny, dense, positively charged central nucleus surrounded by negatively charged electrons
Nuclear Model
The currently accepted atomic model in which electrons are found in orbitals that are positioned around a nucleus that contains protons and (usually) neutrons
Quantum-mechanical Model
The atomic model developed by Niels Bohr in which electrons travel in distinct spherical regions called energy levels at fixed distances from the nucleus
Bohr Model
In the Bohr model of the atom, the regions located at fixed distances from the nucleus of an atom in which electrons are found
Energy Level
The branch of physics that explores the behavior of matter and energy at the atomic and subatomic level
Quantum Mechanics
A helium nucleus that is emitted from a nucleus when a radioactive isotope experiences alpha decay
Alpha Particle
The dense, central portion of an atom
Nucleus
A wave bundle, or particle, of electromagnetic energy
Photon
The region within an atom where an electron will most probably be located; part of the quantum-mechanical model of an atom
Orbital
The basis upon which a model is assessed, taking into account how well it explains or describes a set of observations and how well the model makes predictions
Workability
The smallest of the main subatomic particles, located outside the nucleus, having a negative charge and a mass that is 1/1836th that of a proton
Electron
A subatomic particle found in the nucleus of an atom and having a positive charge and a mass slightly less than that of a neutron
Proton
A subatomic particle found in the nucleus of most atoms that has no electrical charge and a mass slightly greater than that of a proton
Neutron
The unique number of protons found in every atom of a particular element
Atomic Number
An atom of an element that has a different number of neutrons compared with other atoms of that element, resulting in a different mass number
Isotope
The total number of particles found in the nucleus of a particular isotope of an element
Mass Number
A charged atom or group of atoms that has gained or lost electrons, producing an unequal number of protons and electrons
Ion
A negatively charged ion
Anion
A positively charged ion
Cation
The mass of an atom expressed in atomic mass units; the weighted average of the masses of all the naturally occurring isotopes of an element
Atomic Mass
