Total points: 28 [Plus bonus problems, 5 pts.]	ARE YOU REGISTERED? _______
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General
•	You may use a note page, plus the periodic table handout. Otherwise, closed book.
•	Scientific calculator “required”.
•	If a question isn’t clear, please ask me about it.
•	Some questions request a simple answer and an explanation. It’s the explanation that is important. No credit for answer without a requested explanation. 
•	Show clear work with clear units on all calculations; use dimensional analysis (DA) for all conversions. Try to show proper significant figures (SF) in final results. For Test 1, I won’t grade on SF (unless you are quite unreasonable, and in bonus section), but will give you feedback.

Information Densities: water = 1.00 g/mL; copper(II) oxide, 6.49 g/mL; copper 8.94 g/mL; gold 19.3 g/mL; air, 1.2 mg/mL.

•	Although B1 is scored as a Bonus question, I really would like for everyone to do it. It is an attempt to make sure you all are comfortable with some basic calculator functions for scientific notation. Because I need to go over it with you individually, it is helpful if people do it at various times during the period, rather than wait until you are otherwise done.

1. (6 pts.; 1 pt. per part) In each part, give one element with the requested feature. You may give either the name or the symbol. (If you think more than one element fits the question, please give only one.) No explanation needed, but if you give one, it will be considered.

a. 77 protons per atom.

b. 77 electrons per atom.

c. About 77 neutrons per atom, on average. (Explanation encouraged for this one.)

d. About 96 total particles in the nucleus, on average. (Consider only the three major subatomic particles, which are in the parts above.)

e. The heaviest element in period 3.

f. The heaviest metal in period 3.

2. (1 pt.) A news report referred to a 150 [milligram OR kilogram] tuna fish. Choose correct (most likely) term from the brackets, and explain how you can tell. Your explanation should show that you know the difference between the two terms.

3. (1 pt.) A major science story in the news recently has been about the Huygens probe sending back data from Titan, a moon of the planet Saturn. There is much debate about Titan; one proposal is that there may be lakes (or oceans) of methane there, and that there may be methane rain. But methane is a familiar substance on earth; it is the “natural gas” we buy for heating. If this common “natural gas” is rain and lakes on Titan, what does that suggest to you about the conditions on Titan? Explain.

4. (4 pts.) Sodium is a soft silvery-colored solid (a metal), and chlorine is a green gas. If sodium metal is exposed to chlorine gas, you can then find sodium chloride, NaCl.

a. (1 pt.; no credit without explanation) Is this a chemical reaction or merely a physical change? Explain. Your explanation must show that you understand the difference.

b. (1/2 pt.) What is the proper chemical formula for chlorine gas?

c. (1 1/2 pts.) Draw a particulate diagram to show what happens here. 
–	I have started the diagram for you, by showing some atoms of sodium (separate, not bonded to anything). (It may be useful here to think of this reaction as involving all gases.)
–	Don’t forget what you wrote in part b. 
–	Your diagram should be quantitatively correct.

Na		Na
	Na		+				
Na

d. (1 pt.; no credit without explanation) The reactant side (left hand side) of part c shows a (mixture OR compound). Choose correct term from the parentheses. Briefly explain how you can tell.

5. (2 pts.) Calcium compounds are important in bones and teeth. The government standard is that an adult should consume about 1300 mg of Ca per day. How many grams is this? Use dimensional analysis, and show clear work. (Try to show proper SF in the answer. I won’t grade on it, but it is a useful exercise to try it.)

6. (2 pts.; 1 pt. per part) (No credit without explanation.) Consider a piece of iron. It reacts with oxygen in the air, to form iron(III) oxide -- commonly called rust. 

In words: iron metal + oxygen gas gives rust. In symbols: 4 Fe(s) + 3 O2(g)  2 Fe2O3(s). (I have balanced it, but that is not per se important here.)

a. You weigh the piece of iron at the start, and the rust at the end. Which (if either) would you expect to weigh more? Why?

b. Does your answer to part a violate the general idea that mass is conserved in chemical reactions? Explain.

7. (all the pts.) Who are you? Answer at upper right of the odd-numbered pages. No explanation required, but please be specific.

8. (3 pts.; 1 pt. per part) Most of the ideas of chemistry that we have discussed were developed relatively recently (say, in the last 200 years). 2300 years ago Aristotle proposed that matter was composed of four elements: fire, earth, water, and air.

The following parts refer to these Aristotelian elements.

a. Which of these would we now consider to be chemical elements? (In this sense, “which” means any number, from none to all. Specify which ones.)

b. Give one example, from Aristotle’s elements, that we now consider to be a pure chemical substance. What is its chemical formula?

c. Give one example, from Aristotle’s elements, that we would now consider to be “heterogeneous” matter. Briefly explain why you consider it to be heterogeneous.

9. (3 pts.) You have 107 g of a liquid with density 13.6 g/mL.

a. (2 pts.) What is the volume of the liquid? Show clear work, including units.

b. (1 pt.) You now pour one fourth of the liquid into another container. What is the density of that part of the liquid? Show work or explain.

10. (2 pts.) How long does it take light to travel across an atom? Assume that the diameter of an atom is 0.1 nm. The speed of light is 3.0x108 m/s. (n = nano = 10-9.) Use dimensional analysis, and show clear work.

11. (2 pts.) Consider the following scale, which might be found on a graduated cylinder. (It is shown here horizontally, for convenience.)

                                               
							   
    72                                             73                                            74                             mL

a. (1 pt.) What is your “careful” reading for the arrow? (Don’t forget the ???)

b. (1 pt.) If the arrow was a little higher, and you thought it was “exactly” on the next line, how would you record the reading?

12. (2 pts.) A recent paper reported on some special properties of the 88Sr+ ion (that is, a Sr-88 atom that has an altered number of electrons, so that the total charge is now +1). How many protons, electrons, and neutrons are in this ion? Explain how you figure it out. [Go slow. There are three pieces of information. What does each one tell you? Hint: Start with “Sr”. And for those of you who are thinking ahead Yes, this is an unusual ion. ]

BONUS QUESTIONS. (Bonus questions are on next page.) Everyone should do #1! [Tests 1-2 include some “bonus questions”. These may be harder, on more advanced material, or more open-ended than regular questions. They are intended as an extra challenge. Bonus points are scored and recorded separately; they will not normally affect course grade (except possibly in borderline cases). I hope that most students will at least try most bonus questions.]

B1. (2 pts.; must be graded in class; see italicized note) Please have me check this during the test; I will ask you to show me how you did it on your calculator. (The purpose of the question is to promote use of calculator scientific notation functions; see me if you need some calculator help.) Multiply 6.251x1029 by 8.62x10-21 by 1011. Use your scientific calculator. Leave your answer in proper scientific notation. Report the answer with proper SF, assuming that the first two given numbers are measured values.

B2. (1 pt.) An alloy used to make strong magnets is the aptly named Alnico. What are the names of the three major metallic elements used to make Alnico?

B3. (2 pts.) Some human proteins are useful in medical treatments. For example, the protein tPA (tissue plasminogen activator) is sometimes useful in treating heart attack victims; it reduces clotting. One way to make this protein for commercial use is to clone the gene into goats in such a way that the goats excrete it in their milk. The demand for tPA is about 75 kilograms per year. A goat produces about 400 L milk per year. The milk contains about 1 g tPA per liter of milk. Approximately how many goats would be needed to produce enough tPA? Show clear work, with clear units. Use dimensional analysis. (Hint: Consider one year.)

B4. (1 millipoint) 
a. Which member of President Bush’s original cabinet is (was) associated with element #13? Explain. (Not a joke or trick.)

b. Write the chemical formula for his successor; the phase is important.

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Feedback. Any comments/gripes/suggestions about the course so far??? How is the pace? (On “average”, students should spend ~6 hr/wk outside of class on the course.) Use of class time? Homework? In general, what’s good, what’s not? (If this isn’t the time or place, slip me notes any time, or let’s discuss.) (Back of page available.)

cq\pq1	(Sp 05)	
2/22/05