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.
In A Nutshell. Atoms are the smallest pieces of matter; they are made of particles (protons and electrons). When atoms are grouped together, these groups are called molecules (the smallest pieces of compounds). You probably think of atoms, molecules, and particles as all being extremely small pieces of matter.