Relier Pairs Periodic Table Vocabulary (D)Version en ligne Use what you learned from your vocabulary flashcards. par Lydia Lawrence 1 Period 2 Proton 3 Atomic Mass 4 Neutron 5 Group 6 Atom 7 Atomic Number 8 Element 9 Bohr model 10 Electron The number of protons and the number of electrons found in one atom of an element. A subatomic particle located in the nucleus with a positive charge. A basic visual of a single atom with protons, neutrons, and electrons on energy levels. This model was designed by Neils Bohr. The average mass of the protons plus the neutrons in an atom's nucleus. A subatomic particle located on energy levels that has a negative charge. The horizontal rows found on a periodic table. A vertical column on the periodic table. It is also known as a family. The smallest unit a substance can be divided into and still hold the properties of that substance. A subatomic particle located in the nucleus with a neutral, or no, charge. A substance made of one type of atom found on the periodic table. These substances make up everything in the universe.