Presentation on theme: "Element Box page 7 Si Silicon 14 Atomic number Chemical Symbol"— Presentation transcript:
1 Element Box page 7 Si 28.086 Silicon 14 Atomic number Chemical Symbol Atomic massName
2 amu = atomic mass unitThe mass of subatomic particles is so small that a special unit of measurement is needed just for them.1 proton = 1 amu1 neutron = 1 amu1 electron = < 1amuRemember most of an atom’s mass is in the nucleus: p + n* see Gateway p15 : draw each example
3 The number of protons + the number of neutrons Atomic numberThe number of protons found in the nucleusEach atom of an element has a specific number of protons and electrons so no two elements are the same.Atomic MassThe number of protons + the number of neutronsMost of an element’s mass is in the nucleus.
4 Helpful Hints Mass - Atomic # # Neutrons Atomic # = Protons = all the same #Electrons =