1. Atomic Structure Chemistry 11 Ms. McGrath

2. Contributions to the Atomic Theory https://www.youtube.com/watch?v=IO9WS_HNmyg

3. Contributions to the Atomic Theory Aristole Believed matter consisted of: 1. Earth 2. Water 3. Air 4. Fire 5. Aether

4. Contributions to the Atomic Theory Dalton Developed Atomic Theory 1. All matter is composed of atoms 2. Atoms cannot be created or destroyed 3. All atoms of the same element are identical 4. Chemical reactions occur when atoms are rearranged 5. Compounds are formed by the combination of two or more different kinds of atoms

5. Contributions to the Atomic Theory Thomson Atoms could be divided Discovered electrons Revised atomic theory to include electrons Created “Plum Pudding” model (thought electrons were embedded in atom)

6. Contributions to the Atomic Theory Rutherford Discovered protons Believed there was a massive, positively charged particle in the center of the atom Electrons circle the center particle Atoms are composed of mostly empty space

7. Contributions to the Atomic Theory Bohr Transition to modern view of atom Electrons travel around the atom in discrete energy level – “Bohr model” Electrons can move up energy levels if proper energy is applied This amount of energy is “Quantum” of energy

8. Contributions to the Atomic Theory Schrodinger Discovered where electrons are located Because electrons move in “waves” we cannot specifically pinpoint where electrons are located

9. The Atom Complete the following table

10. Electrons Electrons are located in “shells” orbiting the nucleus (which contains the protons and neutrons) Electrons located in the outer shell are called valence electrons The number of valence electrons can be determined by the group number (vertical columns of the periodic table) where the element is located

11. Valence Electrons Identify the number of valence electrons for the following elements: a) chlorinef) lead b) Heliumg) antimony c) indiumh) selenium d) strontiumi) arsenic e) rubidiumj) xenon

12. Atomic Structure Complete the following table based on the relationship between the headings (assume atoms are neutral): Element name Atomic number Mass number Number of protons Number of electrons Number of neutrons a)b)108c)47d) e)f)g)h)42 i)35j)k)l)45 m)79179n)o)p) q)r)s)t)5069

13. Ions Ions are atoms that have gained or lost electrons – in order to satisfy the octet rule (eight valence electrons – hydrogen and helium being exceptions) Cations – positively charged ions. These atoms have lost electrons. Anions – negatively charges ions. These atoms have gained electrons.

14. Ions For each of the following ions, indicate the number of protons and electrons. a) lithium ion, Li + b) calcium ion, Ca 2+ c) bromide ion, Br - d) sulfide ion, S 2-

15. Atomic Symbolism Complete the following table SymbolMass ## of p + # of n 0 # of e - Overall Charge # of valence e - Outermost occupied energy level Mg 2+ 25 910 39200 Y89 182518 732