1.  Turn in your homework if you have it. Lab Sheet and Measuring Matter due tomorrow!!  Date your journal. Title: Atomic Structure

3.  1803 1911 Rutherford  Dalton  1904  JJ Thomson1913 Bohr  Plum pudding

4. A conceptual model of the atom in which a small positively-charged nucleus is surrounded by planetary electrons

6. 1. NUCLEUS  Small Center of the Atom  Made of Protons and Neutrons  Mass of the Atom  Positively Charged 2. ELECTRON CLOUD - Surrounds the Nucleus - Mostly empty space - Where electrons orbit the nucleus - The cloud is huge, the electrons are tiny - The electron cloud has areas where electrons are more likely to be found and areas where they are less likely to be found

7. A football stadium, which represents the atom The nucleus would be in the center on the 50 yd line, but the protons and neutrons that make up the nucleus would be about the size of sesame seeds. Almost all of the mass is here!! The rest of the stadium would be the electron cloud, but the electrons would not be able to be seen if the atom were the size of a football stadium. Atoms are mostly empty space!!!!

8.  Positively charged particles  Help make up the nucleus of the atom  Help identify the atom (could be considered an atom’s DNA)  Equal to the atomic number of the atom  Contribute to the atomic mass  Equal to the number of electrons + + + + + + + + - - - - -- - - +

9.  Neutral particles; have no electric charge  Help make up the nucleus of the atom  Contribute to the atomic mass + + + + + + + - - - - -- - - +

10.  Negatively charged particles  Found outside the nucleus of the atom, in the electron orbits/levels (rings) 2 – 8 - 8  Move so rapidly around the nucleus that they create an electron cloud  Mass is insignificant when compared to protons and neutrons (mass is negligible)  Equal to the number of protons  Involved in the formation of chemical bonds - + + + + + + + - - - - -- - - +

11. Particles that are smaller than the atom PROTONS (p+) in nucleus NEUTRONS (n o ) in nucleus ELECTRONS (e -) in electron cloud