A carbon atom (Superscript 12 C) is represented by two concentric circles of different sizes with the smaller circle having a dark purple color and the larger circle (annulus) having a light purple color. The carbon atom is on a representative weighing balance. At the center of the circles, red and light brown spheres representing protons and neutrons respectively are clumped together forming the nucleus. 6 yellow spheres with minus signs representing electrons are moving continuously and randomly across the concentric circles. Carbon (Superscript 12 C) has 6 protons and 6 neutrons and therefore has a mass number of 12. It also has 6 electrons.
