Aubrey High School AP Chemistry 8 Atomic Theory Name Period Date / / 8.0 Prep Problems History of the Atom 1. Describe the contributions of the following scientists and their research to the theory of the structure of atoms. (Many of these can be reviewed at https://www.youtube.com/watch?v=c2y_-t7kkgk) Scientist Year Research Discovery/Theory Model of Atom Limitations Democritus John Dalton J.J. Thomson 1897 Cathode Ray Tube Experiments Discovered the electron Plum Pudding Model Atom is mainly empty space. Ernest Rutherford Neils Bohr Based on Balmer s hydrogen spectral lines Erwin Schrödinger Werner Heisenberg Other scientists with whom to be familiar: Antoine Lavoisier, Benjamin Franklin, Joseph Priestley, Amedeo Avogadro, Michael Faraday, Dmitri Mendeleev, Johannes van der Waals, Johann Balmer, Antoine Becquerel, Max Planck, Albert Einstein, William Henry Bragg, Louis de Broglie, Wolfgang Pauli, Linus Pauling, James Chadwick, Glenn Seaborg. Atomic Structure 2. Draw a representation of the following atoms, indicating the numbers of protons, neutrons, and electrons. a. 22 Ne b. 52 Cr 3+ c. 32 S 2
3. Silicon exists in three isotopes: Si-28, Si-29, and Si-30. Calculate the atomic mass of silicon, based on the following data. Isotope Isotopic Mass Percent Abundance Si-28 27.9769 amu 92.2297% Si-29 28.9765 amu 4.6832% Si-30 29.9738 amu 3.0872% Electromagnetic Radiation 6. Arrange the following forms of electromagnetic radiation from lowest frequency to highest frequency. Indicate how their wavelengths (short to long) and their energies (low to high) compare. Gamma rays, infrared radiation, microwaves, radio waves, ultraviolet radiation, visible light, X-rays. 4. Lithium exists is two isotopes: Li 6, which has a mass of 6.0151 amu, and Li 7, which has a mass of 7.0160 amu. If the atomic mass of lithium is 6.94 amu, what is the abundance of each isotope? 7. The C=O bond stretches at 5.71 10 6 m. What is the energy and frequency of this stretch? c = λ ν, E = h ν, c = 3.0 10 8 m/s, h = 6.626 10 34 J s. 5. The following mass spectra was given for magnesium. Use this data to calculate the atomic mass of magnesium. Atomic Orbitals Write the atomic orbital that is filled in each block. Mass Intensity 23.98505 100.00 24.98584 12.674 25.98260 14.068 List the atomic orbitals from lowest to highest energy (1s, 2s, 2p,...)
10. Determine each of the following. a. How many electrons can fill the 4f subshell? b. How many total orbitals are in the n = 5 electron shell? c. How many orbitals are in the 3d subshell? d. How many subshells are in the n = 7 electron shell? e. How many electrons can fill the n = 2 electron shell? Electron Configuration 11. Write the long form ground state electron configuration for the following. Circle the valence electrons. a. Sr 13. Draw how the highest-energy subshell is filled in each of these. State the number of half-filled orbitals. a. As b. Fe c. Sb d. Ba 14. Determine the ion each element likely forms. a. Ga b. Co c. Rb d. Te b. Br c. Sn 2+ d. Cu 2+ Periodic Trends 15. State with an explanation the following trends: a. For elements across a period from left to right, the atomic radius [increases decreases], ionization energy [increases decreases], and electronegativity [increases decreases] because: 12. Write the short form ground state electron configuration for the following. Circle the valence electrons. e. Ar f. Au 2+ b. For elements down a group from top to bottom, the atomic radius [increases decreases], ionization energy [increases decreases], and electronegativity [increases decreases] because: g. I h. Bi 5+ c. Indicate the trends above on the Periodic Table below:
16. Select each of the following and provide a brief explanation. a. Smaller radius O or O 2- b. Larger radius Se2- or Kr c. Higher 2nd ionization energy Na or Mg 17. Determine the most likely ion formed by this element using successive ionization energies. IE 1 = 550 kj/mol IE 2 = 1,064 kj/mol IE 3 = 4,138 kj/mol IE 4 = 5,500 kj/mol IE 5 = 6,910 kj/mol d. Lower electronegativity Sn or Pb e. Smaller radius Na+ or Mg+ f. Lower ionization energy Mg or K g. Smaller radius Sr or Sr2+ h. Higher electronegativity Se or Te i. Lower ionization energy Be+ or Be2+ j. Larger radius Zn or Ag k. Larger radius Br- or Rb+ l. Smaller radius Al or Si m. Lower electronegativity Cs or Ba n. Larger radius K or Rb