Chapter 4 Vocab Flashcards
The Greek philosopher who said that you could cut an atom into a particle that could not be cut.
Democritus
Was the first scientist to make an atomic theory based on experiments.
John Dalton
Scientist who discovered electrons and smaller particles inside the atoms.
J.J. Thomson
A scientist who used a gold foil experiment and revised the atomic theory which had a nucleus in it.
Ernest Rutherford
A scientist who discovered energy levels in which the electrons move around in.
Niels Bohr
A theory made by two scientists that electrons are most likely to be found in regions called electron clouds.
Modern Atomic Theory
The smallest unit of an element that maintains the properties of an element.
Atom
A subatomic particle that has a negative charge.
Electron
In physical science, an atom’s central region, which is made up of protons and neutrons.
Nucleus
A region around the nucleus of an atom where electrons are likely to be found.
Electron Clouds
A subatomic particle that has a positive charge and that is found in the nucleus of an atom.
Proton
A unit of mass that describes the mass of an atom or molecule.
Atomic Mass Unit
A subatomic particle that has no charge and that is found in the nucleus of an atom.
Neutron
The number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element.
Atomic Number
An atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass)
Isotope
