Today is 6 February 2008 -- Please complete the following "Basic Science Skills" assessment.

Download the assessment or copy to a word processor. You may turn in your work on-line or in class.

1. What is 5/8 of 16/30?

2. Divide 27/32 by 3/8.

3. The concentration of a chemical in a mixture is 0.023%. How much of the chemical is in 78 grams?

4. 3/8 of a pound of iron is added to 2/3 of a pound of carbon. What is the total weight?

5. 3/26 of an ounce of magnesium oxide is taken from 29/13 ounces of it. How much is left?

6. How many feet in a yard?

7. How many inches in a yard?

8. How many centimeters in an inch?

9. How many centimeters in a yard?

10. 200 milligrams of a substance is added to 2.79 grams of the same substance. What percentage has been added?

11. A mixture is analyzed. It contains 4.5 grams of “A,” 17.06 grams of “B,” 0.06 grams of “C” and the balance is “D.” The overall weight is 30.19 grams. How much “D” is present? What is the percentage each of A, B, C and D in the mixture?

12. Express 0.0011 in scientific notation.

13. What is “standard format?” Give an example.

14. Express 3,259,609 in scientific notation.

15. How many significant figures in each of the following (NOTE: Not multiple choice!):

a. 3.104?

b. 1.0400?

c. 4000?

d. 0.0023

e. 1.9 x 10-3

16. The formula for a certain chemical compound is HxSyOz where "x, y and z" are subscripts that tell how many of a particular atom is present. For example, H2O -- water contains two atoms of hydrogen and one atom of oxygen for a total of three atoms in the molecule. Now, for the problem, if z = 4, x = 1/2 z and y = 1/2 x, how many atoms are present?

17. Carbon-14 is a radioactive isotope of carbon that decays to nitrogen at a predictable rate. The decay rate is used as a "clock" to determine the date of archelogical specimens. The "half-life" is the time it takes for one half of the radioactive carbon in a sample to decay. The half life for carbon-14 is 5730 years. In other words, if you have 10 grams of carbon-14 to begin with, then after one half life, you have 5 grams left. (Make sure you understand the question. Explain to yourself what "half-life" means. )

a. How many half lives will have passed if the sample has 2.5 grams of carbon-14 left?

b. How many years will have passed in two half-lives for carbon-14?

18. The atomic weight of methane gas (CH4) is 16. The atomic weight of air is about 29. This means that methane gas is less dense than air so it will rise. We can demonstrate this by blowing a soap bubble with gas. As it rises, we can touch a flame to the bubble and watch it ignite. It's really fun to watch. But here is my question: if the bubble is 4 inches in diameter, how much gas is in it? (In other words, what is the volume of a sphere whose diameter is 4 inches? The formula is V = (4/3) x Pi (the value is 3.14, if you have forgotten) x radius cubed.

19. In biology and chemistry we often use equations of the form A = B divided by C. (A=B/C). If you know any two of these variables, you can solve for the third. For example, the volume (V) of a solid is 5.75 cubic inches and its mass (m) is 11.50 lbs. What is the density? (D = m / V)

20. This is the last question and it contains a trick. Think carefully before you answer.

a. What is the order of the numbers 1, 3, 5, 7, 9 ?

b. What is the order of the numbers 2, 4, 8, 16, 32, 64 ?

c. What is the order of the numbers eight, five, four, nine, one, seven, six, three, two, zero?