TOPICS ON THE TEST History of Atomic Theory –Scientists –Their contribution Atomic Structure –Subatomic Particles –Atomic Charts –Average Atomic Mass Problems

ANCIENT TIMES Greeks Aristotle –four element theory –Matter is continuous. Democritus –empty space and atoms Alchemists –first to experiment –invented glassware

1600’S AND 1700’S Boyle –first to define an element Lavoisier –accurate experiments –wrote first chemistry book Priestly –isolated oxygen –carbonated water

1800’s Dalton –“Father of the Atomic Theory” –Four Point Theory Elements are made of atoms. Atoms of the same element are identical. Law of Multiple Proportions Chemical Reaction - rearrangement of atoms

1800’s Gay-Lussac –Law of Combining Volumes Avogadro –Equal volumes of gas have equal number of particles at same temp. and pressure. Thomson –Discovered the electron

1900’s Millikan –Charge of an electron Bohr –Electrons orbit around the nucleus like planets orbit the sun. Rutherford –Discovered the nucleus

1900’s Chadwick –Discovered the neutron

ATOMIC STRUCTURE Subatomic Particles –protons, neutrons, and electrons –location, charge, symbol, mass

ATOMIC CHARTS Be able to find: –name of element –symbol of element –atomic number –mass number –number of protons –number of neutrons –number of electrons

AVERAGE ATOMIC MASS Example: