Chapter 4 Flashcards
The smallest unit of an element that maintains the properties of that 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 Cloud
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; AMU
A subatomic particle that has no charge that is found in the nucleus of an atom
Neutron
The number of protons in the nucleus of an atom; 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 has a different number of neutrons (and this a different atomic mass)
Isoptope
The sum of the numbers of protons and neutrons in the nucleus of an atom
Mass Number
The mass of an atom expressed in atomic mass units
Atomic Mass
Thought of the idea that you could break a substance, than reach a particle that could not be broken
Democritis
Took Democritis’ idea and experimented with different substances
Dalton
Discovered that there are smaller particles inside an atom; made a plum pudding model
Thomson
Made the “shooting gallery” experiment. Experimented with gold foil and light to see how the particles moved with light.
Rutherford
