1. THINK FIRST DO NOT LET THIS BE YOU ON THE TEST DAY. ASK QUESTIONS SO WE CAN FIGURE IT OUT. In your composition book, write down 2 or more questions that are not clear. If you understand everything, help your neighbor answer their questions. Finish by: _______________

2. Chapter 4 What did we learn? The atomic number (# of protons) determines an element An isotope has extra neutrons, and therefore extra weight. How do you calculate # of neutrons? If an element has many isotopes, we need to use an average mass! Why??? How do we calculate this? Who contributed to our understanding of an atom? Dalton, Thomson’s Cathode Ray, Rutherford’s Gold Foil, Bohr, Millikan…

3. Practice Problems How many electrons, neutrons, and protons are in Nitrogen-15? How do we write this? How about Nitrogen-17?

4. How do we calculate average atomic mass? mass 1 x percentage 1 = mass 2 x percentage 2 = mass …n x percentage …n = Σ__________ Calculate the average atomic mass of these three isotopes. 40 K at 89% 19 41 K at 7% 19 44 K at 4% 19

5. Chapter 5 What did we learn? # electrons in atom = # protons Electrons are arranged in energy levels and can move around (quantums!) How do we arrange these electrons and write this configuration out? Light behaves as both a wave and particle. How do we calculate energy of a photon and the frequency or wavelength of a wave?

6. Practice Problems What is the electron configuration of these elements? 40 K 19 73 Ge 32 9 B 4

7. Which rules do these violate? 1s 1 2s 2 2p 2 3s 2 1s 2 2s 2 2p 6 3s 2 3p 7 What is the electron configuration for these elements? Mg Ar Sr

8. Photons and Quantums Electrons can absorb and emit energy. What are some examples of this in our daily life?

9. c = λν E=hν If a wave has a wavelength of 7.80 x 10 -7 (IR light), what is the frequency? What is the energy of the photon?

10. Chapter 25.1 What did we learn? There are 3 basic types of nuclear radiation (alpha, beta, gamma) with special properties each. We can write out these equations using a simple set-up and balancing the number of protons and atomic mass on each side.

11. Alpha radiation is not that harmful unless ingested into the body. Why is this? Would you be more worried about alpha or gamma radiation? Why?

12. Reactants → Products If something is produced, it’s a product! If it reacts, undergoes, or we start with it, it’s a reactant! Cerium-142 undergoes beta-decay. Write this equation. Uranium-240 is produced from beta-decay. Write this equation.