Atoms and Elements Atoms: the smallest whole particle of matter. ­groups of atoms make up molecules ­groups of molecules make up substances. Mar 19­11:58 AM 1 Electrons ­ Negatively charged particles. Protons­ Positively charged particles Neutrons­ Nucleus ­ Made up of Protons and Neutrons Have no charge Mar 19­8:11 AM 2 What is an element and how many are there? How are they sorted? Elements - Substance made up of only 1 type of atom. There are more than 100 elements They are sorted by size and structure in the Periodic Table Mar 20­7:30 AM 3 Mar 20­7:27 AM 4 What facts can you tell me about a gold atom based on its chemical symbol? Atomic Number: 79 Atomic Mass: 196.966569 Mass Number: 197 Protons: 79 Neutrons: 197-79 = 118 Electrons: 79 What can you conclude about this element compared to other elements you know about? Mar 22­7:35 AM 5