Relier Pairs Periodic Table Vocabulary (D)Version en ligne Use what you learned from your vocabulary flashcards. par Lydia Lawrence 1 Atomic Number 2 Atom 3 Bohr model 4 Neutron 5 Atomic Mass 6 Element 7 Electron 8 Period 9 Group 10 Proton 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. A subatomic particle located in the nucleus with a positive charge. A subatomic particle located in the nucleus with a neutral, or no, charge. A basic visual of a single atom with protons, neutrons, and electrons on energy levels. This model was designed by Neils Bohr. A substance made of one type of atom found on the periodic table. These substances make up everything in the universe. The number of protons and the number of electrons found in one atom of an element. 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.