Review Sheet for Unit 2 Chapters 3, 4 , 5 and 24 Mass ( amu) % abundance Mass number 32.033 95.029 33.144 .754 33.744 4.218 36.021 .021 1. Complete the chart and use your answer the chart for questions 2 - 8 2. Determine the average atomic mass. 3. What element is this? 4. How many protons, electrons and neutrons does this element have? 5. What is the charge of its nucleus? 6. Give the electron configuration in both the ground state and the excited state. 7. Draw the Bohr model and the orbital diagram for the address of this element. 8. Draw the Lewis dot diagram for this element. 9. Give the electron configuration for the element with the address 4f2. You may use short hand notation. 10. Name two elements that have 3 valence electrons. 11. How can light be created from exciting electrons? 12. Give the electron configuration for Mg +2. 13. What is the difference between an ion and an isotope? 14. Why does radioactive material decay? 15. Put the radioactive decays in descending order. 16. Which decay loses an electron? Which decay loses 2 protons and two neutrons? 17. In a nuclear reaction what can change? In a chemical reaction what can change? 18. What are the two types of nuclear reactions? Explain how they are different. Which reaction is occurring in stars? Which reaction is responsible for elements being made? Which reaction is occurring in nuclear power plants? 19. The half- life of Iodine -131 is 8 days. What mass of I -131 remains from a 4.00 g sample after 48 days? 20. The half-life of Carbon -14 is about 5700 years. If a relic was found to contain 1/16th the original amount what is the age of the relic? 21. The half-life of a radioactive isotope is 15 days. What mass will remain after 45 days given the original mass started at 46.0 g? 22. Lead is a well known heavy metal with a density of 11.53 g/ cm3. What would be the volume of lead given that you have a 0.255 pound sample? ( 2.2 lbs = 1 kg) 23. If you are driving at a speed of 25 mph, how long would it take you to go 344 km? 24. Give the electron configuration of Mercury. Draw its Bohr model, give the Lewis dot diagram and the orbital diagram of its address. 25. What element is [Kr] 5s2 4d4? 26. Give the electron configuration of an excited Strontium atom.