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.
Atomic Structure Definition. 1  Inside the nucleus, protons and neutrons are present which are collectively called nucleons. 2  The electrons are revolving around the nucleus in fixed orbits. 3  The mass of an atom is concentrated inside the nucleus of an atom. 4  Atom is electrically neutral.