1. Atomic Structure What are atoms made of? How are atoms put together? What are Elements? Isotopes?

2. Atomic Structure Protons- Neutrons- Electrons-

3. Proton (p) Positive Charge (+1) Nucleon (located in nucleus) Proton population determines which element (atomic number = number of protons) Relative Mass = 1 (approx. same as neutron)

4. Neutron (n) No Charge (neutral) Nucleon (located in nucleus) Neutron population determines which isotope (mass number= number of protons + number of neutrons) Relative Mass = 1 (approx. same as proton)

5. Electrons (e-) Negative Charge (-1) Located outside nucleus Electron population is equal to proton population in atom Relative Mass = 1/1800 (very small compared to nucleons)

6. Ions CationAnion

7. Chemical Notation

8. Elements and Isotopes Elements Determined by atomic number (# of protons) Have unique chemical properties, based on differing electron configurations Isotopes Same element, but different number of neutrons Have same chemical properties, based on identical electron configurations

9. Isotopes and Atomic Mass Atomic Mass is the weighted average of the masses of all isotopes of an element as it is found in nature A.M. = R.A. 1 (mass 1 ) + R.A. 2 (mass 2 ) +... R.A. = Relative Abundance Ex. Cl- 35 and Cl- 37 are two isotopes of chlorine. R.A. 35 = 77.5% and R.A. 37 = 22.5%, what is A.M. of Chlorine?

10. Practice Problem Element Bengiovannium exists as 3 isotopes; Bg-357, Bg-359, Bg-360. The R.A. of the lighter 2 are 41.3% and 16.2% respectively. What is the atomic mass of Bengiovannium?

11. Challenge Problem Element A, exists in 2 isotopes; A-27 and A-30. The atomic mass of Element A = 28.42 amu. What are the relative abundances of each isotope?