An atom is the smallest unit of matter that has the properties of an element. It is composed of a dense core called the nucleus and a series of outer shells occupied by orbiting electrons. ... The atomic number of an atom is dictated by the number of protons, which in turn, determines the chemical element of the atom.Quarks are the smallest particles we have come across in our scientific endeavor. Discovery of quarks meant that protons and neutrons weren't fundamental anymore. For more thorough understanding let's peel apart a piece of matter and discover its constituents by removing each layer one by one.
