1. John Dalton agreed with Democritus that atoms exist. What were the main concepts of his theory? 2. Through what experiment was JJ Thomson able to provide his model of the atom. What subatomic particle is his significant addition to the theory? 3. Sketch Rutherford’s Gold Foil Experiment set up. What subatomic particle did he observe? Explain the outcome of his experiment. 4. Draw the Bohr model of the atom. What was his significant contribution to atomic theory? His model was the first to show ________ _______.

 Dalton was the father of modern atomic theory. The concepts of his theory were that all matter was made up of atoms, atoms in the same element are identical, and described chemical reactions.  Cathode ray experiment. JJ Thomson discovered electrons.

 Rutherford observed positively charged protons. His experiment demonstrated that after particles collided with the nucleus of the gold atoms in the gold foil, they traveled into different directions.  He established that electrons were organized into levels based on their energy within the electron cloud. His model was the first to show energy levels.

1. How many protons are in bismuth-209? 2. How many electrons are in Sb -3 ? 3. Name the significance of each of the subatomic particles. 4. How do the subatomic particles compare in terms of mass?

 83 Protons  54 Electrons  PROTONS – determine the identity, = to Atomic number; NEUTRONS – Change to form isotopes, neutrons + protons = mass number; ELECTRONS – Determine chemical properties, Change to form ions or give the atom charge (Oxidation state)  Protons and Neutrons are relatively large and similar and mass. Electrons are very small and do NOT affect the mass of the atom

1. Define isotope. 2. Calculate the atomic mass of neon. The three isotopes occur in the following abundances: 20 Ne=90.92%, 21 Ne=0.257% and 22 Ne=8.82% 3. If you were missing the percent of one of the isotopes above, would the problem be incomplete and unsolvable? If not, how would you find the missing percent?

 Isotope –Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei  Atomic Mass = amu  The problem would not be incomplete. Subtract the percent that you have from 100 to find the missing percent.

1. What is the difference between relative and percent abundance? 2. Element D has 2 naturally occurring isotopes and its atomic mass is 2.345amu. D-3.0 has a mass of 3amu and D-2 has a mass of 2.1amu. Calculate the relative and percent abundance for each. 3. Checking your answer: Your atomic mass should be closest to the isotope with the ________ (lowest/highest) percent abundance.

 Both determine how much of the isotope is found in nature compared to the other isotopes. Relative abundance is in decimal form and percent abundance is in percent form.  D-3 (RA =.2702, PA = 27.02%) D-2 (RA =.7278, PA = 72.78%)  Highest

1. Which electron configuration rule states that electrons fill the orbitals on the lowest energy level first? 2. How many unpaired electrons are in C? 3. How many valence electrons are in Ca? Ag? 4. Write the electron configuration for Ni. Draw the orbital diagram. 5. Write the noble gas notation for iodine.

 Aufbau Principle  2 electrons are unpaired  Ca has 2 valence electrons. Ag has 2 valence electrons.  Ni has 28 electrons (1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 8 )  Iodine Noble Gas Notation: [Kr]5s 2 4d 10 5p 5

1. Describe the process of an atom giving off a wave of light. 2. Which color of visible light has the highest frequency? Energy? 3. What color of visible light has the shortest wavelength? Longest wavelength? 4. What is the energy of a wave with a wavelength of 470 nm? c = 3.0x10 8 m/sh = 6.626x Js

 Electron absorbs energy and jumps to a higher level (excited state) for a lower level (ground state). The excitation is only temporary. When the electron falls back to ground state emission of light occurs in the form of a wave.  Violet, Violet  Violet, Red