Presentation on theme: "Atom Notes Atom – small particle that makes up most types of matter (One million atoms lined up equals the thickness of one human hair) Atomic structure."— Presentation transcript:
1 Atom NotesAtom – small particle that makes up most types of matter (One million atoms lined up equals the thickness of one human hair)Atomic structureNucleus – central part of an atomProtons – positively charged particles in the nucleus of an atomNeutrons – uncharged particles in the nucleus of an atomElectrons - negatively charged particles in an atom
3 History of Atomic Theory Dalton – (atomic model) Theory that substances were made of atoms, small, hard, dense spheres that could not be created, destroyed, or altered.Dalton’s model of the atomJohn Dalton
4 History of Atomic Theory Thomson – (discovering the electron) Proposed that atoms were made up of smaller particles. Theory that smaller negatively charged particles are spread evenly around a positively charged nucleus. His model was called the plum-pudding model.
5 History of Atomic Theory Rutherford – (the nucleus) Proposed that atoms had a dense, positively charged nucleus surrounded by electrons.Chadwick – discovered the neutronsRutherford’s model
6 History of Atomic Theory Bohr – Said that electrons revolve around the nucleus in circular paths or orbits and that electrons could only exist in certain orbits and at certain energy levels.nitrogenExample of Bohr’s model of the atom
7 Periodic TableMendeleev – arranged 63 elements into groups based on their chemical properties and atomic weights.
9 Periodic Table Element name Atomic number Symbol State of matter Atomic massHydrogen1H1.008
10 Element Information For any element: Number of Protons = Atomic Number Number of Electrons = Number of Protons = Atomic NumberNumber of Neutrons = Mass Number - Atomic NumberMass number = Protons + Neutrons (not found on periodic table)
11 IsotopesIsotopes have the same number of protons but a different mass number.Example: Carbon – and Carbon –14Average atomic mass is an average of all the isotopes (can be found on the periodic table)
12 Draw atomsShell ## of electronsin shell1283184325
13 Metal, Nonmetal, Metalloid Metals – good conductors -malleable and ductile -lose electronsNonmetals – poor conductors -brittle -gain electrons -form covalent bondsMetalloids – show properties of both metals and nonmetals.