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