Relier Pairs Atoms and APEMANVersion en ligne Parts of the atom and APEMAN matching (8.5A) par James Dycus 1 2 N 3 4 A (M-A) 5 M 6 7 8 P 9 10 11 E 12 A 13 Number of Protons Atomic Mass The dense and compact core of the atom that contains all of the protons and neutrons. (Nucleus) Number of Neutrons Electrons located in the outermost electron shell. This is the shell responsible for chemical reactivity. (Valence Electron) Circular areas that make up the electron cloud. These shells are the path that electrons take as they constantly move around the nucleus. (Energy Shells/Electron Shells) Atomic Number Number of Electrons Atomic Number (M-A) Subatomic particle that has a negative (-1) charge and has zero atomic mass units (0 amu) (Electron) Subatomic particle with a neutral (0) charge and a mass of 1 atomic mass unit (1 amu) (Neutron) Subatomic particle with a positive (+1) charge and a mass of 1 atomic mass unit (1 amu) (Proton) Area located outside of the dense compact core. This area is mostly empty space and is where all the electrons are located. (Electron Cloud)