3. (3) For each of the following measurements, state the number of significant figures, the uncertainty, and the range of possible values.

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1 Exam 1 Chem 30A, Fall 11 Fossum Name: Note: there are 5 points of extra credit built in to this exam. 1. (2) Shown here is a close-up of part of a ruler. The units are centimeters. If you were measuring with this ruler and your object came to the length indicated by the arrow, what would be the length of the object to the nearest 0.01 cm? (You must interpolate!) 2. (3) How many protons, electrons and neutrons are in 58 Fe? 3. (3) For each of the following measurements, state the number of significant figures, the uncertainty, and the range of possible values g 7600 ml 4. (3) Write the symbol of each of the following elements. argon barium gold 5. (3) Write the name for each of the following elements. Si Pb Ne 6. (4) For each of the following atoms, state the number of valence electrons and write the electron-dot symbol for the atom. P O 7. (3) Predict the charge on an ion of: fluorine phosphorus magnesium 8. (1) Write the following number in scientific notation: (1) Write the following as a regular number:

2 10. (4) Give three examples of elements in each of the following categories. a. main group elements in the 2 nd period b. alkaline earth elements b. transition elements d. metals 11. (2) State whether each of the following is a chemical property or a physical property: a. Sodium carbonate will react with any strong acid. b. Acetone has a freezing point of - 94 C. 12. (2) For the element Ca: what other elements (list them) would you expect to have similar properties compared to Ca? Explain your reasoning. 13. (2) Convert 301 K to C. 14. (2) Draw the arrow diagram for sulfur. 15. (4) a. Write the full electron configuration of Cl. b. Write the full electron configuration of Ti. 16. (2) Write the abbreviated electron configuration (noble gas notation) of Sn (atomic number 50). 17. (2) Write the electron configuration of Ca 2+. 2

3 18. (2) Do electrons orbit the nucleus in definite circular paths? Explain. 19. (2) What is the significance of having a filled shell of electrons? 20. (2) If two atoms are isotopes of each other, what is similar about the atoms and what is different about them? 21. (3) A blue liquid was heated for a long time, and the vapor was captured, cooled, and condensed. The condensed vapor was a clear, colorless liquid. After the heating was complete, there was a blue solid left in the original container. Was the original blue liquid an element, a compound, or a mixture? Explain how you can tell. 22. (2) Why are gases compressible? Why aren t liquids compressible? Explain. 23. (3 points) The specific heat of copper is J/g C. The specific heat of iron is J/g C. a. Which metal will heat up faster? How can you tell? b. Which metal will cool off faster? Why? 3

4 24. (6) Perform each of the following calculations and round the result to the correct number of significant figures. No credit will be given if the number of significant figures is incorrect. a = b = c = d. ( ) = 25. a. (2) Sketch a 1s orbital and a 2s orbital. How are they different? b. (2) Sketch a p orbital and a d orbital. 26. (4) Wavelengths of light are often expressed in units of nanometers. Convert 475 nm to meters. b. Explain why your answer makes sense. (Is your result large, medium or small, and why?) 27. (4) Given the following data from a laboratory, calculate the density of the liquid. Mass of empty graduated cylinder Mass of graduated cylinder plus liquid Volume of liquid in graduated cylinder g g 16.5 ml 4

5 28. (6) a. The average price of regular gas in British Columbia, Canada was $1.32 Canadian dollars per liter on Sept 17, Convert this to US dollars per gallon. exchange rate as of Sept 16, 2011: 1 US dollar = Canadian dollars b. Comment on the result of the calculation. 29. (7 points) Gasoline has a density of 0.68 g/ml. What is the volume of 8.00 kg of gasoline, in liters? What is the volume in gallons? What is the mass in pounds? 30. (6 points) The specific heat of tungsten (W) is cal/g C. If kj of heat are added to a 15.0 g piece of tungsten that is initially at 19 C, calculate the final temperature of the piece of tungsten. 5

6 31. (6) A hospital patient has a fever and weighs 155 pounds. He is to receive medication for his fever. The recommended dosage of this medication is 1.2 mg of the drug per kilogram of body weight. The drug is dissolved in water at a concentration of 30.0 mg per milliliter of water. How many milliliters of the drug solution should the patient be given? 32. (5 points) Calculate the weighted-average atomic mass of Fe, given the following isotope abundances and masses. isotope Mass in amu abundance 54 Fe % 56 Fe % 57 Fe % 58 Fe % 6