Sleep Number King Size 2-3 inch Mattress Bed Foam Topper Pad 7000, i8, i9.
Quick Answer. The three parts of an atom are the protons, neutrons and electrons. Atoms make up the basic building blocks of matter and define the structure of elements. These parts were not officially identified until 1932.
The number of protons in the nucleus of an atom; the atomic # is the same for all atoms of an elements. Atomic Number: A region around the nucleus of an atom where electrons are likely to be found. Electron Cloud: A unit of massthat describes the mass of an atom or molecule. Atomic Mass Unit