4 Introduction to Atoms Flashcards
Atom
The smallest unit of an element that maintains the properties of that elements.
Electrons
A subatomic particles that has a negative charge.
Nucleus
In physical science , an atom’s central region, which is made up of protons and neutrons.
Electron Clouds
A region around the nucleus of an atom where electrons are likely to be found.
Protons
A subatomic particles that has a positive charge and that is found in the nucleus of an atom.
Atomic mass unit
A unit of mass the describes the mass of an atom or molecule.
Neutrons
A subatomic particle that has no charge and that is found in the nucleus of an atom.
Atomic Number
The number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element.
Isotopes
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)
Mass number
The sum of the numbers of protons and neutrons in the nucleus of an atom.
Atomic mass
The mass of an atom expressed in atomic mass unit