Science & Mathematics - 3 October 2007

A pharmaceutical chemist runs a chromatography test on a substance and identifies two of its components by comparing their Rf values against certain standards. If the two components have Rf values of 1.0 and 0.41 and the solvent front has traveled 12.0 cm from the samples origin, what is the separation distance on the chromatogram??

2007-10-03 19:23:06 · 2 answers · asked by Anonymous in Chemistry

2007-10-03 19:22:20 · 3 answers · asked by Anonymous in Chemistry

Would anyone know how to show that Log(base 10) x is big Theta (Log(base 2) x) if anything hints would be fine.

2007-10-03 19:21:57 · 2 answers · asked by Carlos 2 in Mathematics

Also, where can I look to find the expected Rf value for this solute in the solvent you suggested. Thank you in advance.

2007-10-03 19:18:50 · 1 answers · asked by lhvinny 7 in Chemistry

I sometimes just know an event is going to happen. I get panicky, and then I find out the event actually happened. I am fuzzy on details though. i.e. I suddenly knew that there would be a car accident and the vehicle would be totalled. I thought it meant it would happen to me. It happened later in the day to my two stepdaughters that I had not even met at the time. They were driving across country to live with us. These are more than thoughts or feelings. What is this? and where does it come from?

2007-10-03 19:17:18 · 6 answers · asked by Dynamic H 2 in Parapsychology

best answers 2 whoever gives best explanation!

2007-10-03 19:12:34 · 4 answers · asked by Anonymous in Mathematics

A pharmaceutical chemist runs a chromatography test on a substance and identifies two of its components by comparing their Rf values against certain standards. If the two components have Rf values of 1.0 and 0.41 and the solvent front has traveled 12.0 cm from the samples origin, what is the separation distance on the chromatogram??

2007-10-03 19:09:01 · 1 answers · asked by Anonymous in Chemistry

A copper atom has a diameter of 127.8 pm (10^ -12 m=1 pm). What is the length in meters of a line containing 1.000 mols of copper atoms? Thanks!

2007-10-03 19:06:07 · 3 answers · asked by Anita 5 in Chemistry

2007-10-03 19:04:40 · 25 answers · asked by Artiecat 1 in Astronomy & Space

2007-10-03 19:03:19 · 8 answers · asked by Anikin 1 in Astronomy & Space

2007-10-03 19:01:44 · 1 answers · asked by xxbabycheekzix 1 in Chemistry

2007-10-03 18:59:30 · 2 answers · asked by jennifer f 1 in Chemistry

2007-10-03 18:58:52 · 1 answers · asked by jennifer f 1 in Chemistry

2007-10-03 18:58:01 · 1 answers · asked by jennifer f 1 in Chemistry

Eighty-Four quarters are lined up side by side on a table. You begin by replacing every second quarter with a dime. After you have completed this task, you replace every third coin with a nickel. Once this is completed, you replace every fourth coin with a penny. What is the total value of the final 84 coins on the table?

2007-10-03 18:57:43 · 5 answers · asked by pr3ttyinpinkrgv 1 in Mathematics

Lol, me again, Ok so I've been working on this problem for about 20 min and I CAN'T get it ): I bet it's easy :/ So the question is a average huffamoose has a mass of 3400kg. How many mg? Now this is Dimensional Analysis. I need explanation. Thanks so much (:

2007-10-03 18:56:37 · 3 answers · asked by Jazzy 1 in Physics

write c in the form ra+sb, where r and s are scalars.

a=3i+2j
b+8i+5j
c+7i+9j

2007-10-03 18:56:18 · 2 answers · asked by Jebediah T 1 in Mathematics

Many people claim that the greenhouse effect is to blame for global warming, but i dont. Now, i do believe that chemicals do play a part in global warming but it is not the main problem. I have a theory that explains whats really causing global warming. The theory is called the photosynthesis effect. It is when the tree and plant population declines and therefore cant absorb carbon dioxide during photosynthesis. So the carbon dioxide stays in our planet causing a tramendious heat increase. But the problem can be solved by replanting trees as well as other plant life, in which would absorb the carbon dioxide during photosynthesis. If venus had plant life then it would probably be cooler as well. What do you think about the photosynthesis theory that i have created.

2007-10-03 18:56:17 · 5 answers · asked by Anonymous in Botany

chlorine solution + potassium iodide solution -> ???
and what is the symbol equation???

2007-10-03 18:54:04 · 2 answers · asked by *gemma* 2 in Chemistry

2007-10-03 18:44:24 · 5 answers · asked by Shantel 1 in Earth Sciences & Geology

1. After mitosis occurs to a single cell, how many cells result?
a. 2
b. 3
c. 4
d. 5

2. What causes growth?
a. mitosis
b. meiosis
c. anaphase
d. telophase

3. How many genes are on a single chromosome?
a. 2
b. 50
c. 100
d. sometimes thousands

2007-10-03 18:34:58 · 6 answers · asked by Anonymous in Biology

you are conducting an experiment to measure the gain in mass of a young mouse over a ten-week period.in constructing a graph to represent your data, which variable should you place along the x-axis and which variable should you place along the y-axis? Explain your answer

2007-10-03 18:34:30 · 3 answers · asked by Anonymous in Biology

Thanks, please include all steps so I can see how you got it.

2007-10-03 18:21:35 · 5 answers · asked by Anonymous in Physics

Is the math less intense in a radiography program than a radiation therapy program? And also to any rad techs and/or radiation therapy techs what are the health risks is it true you have to take medicine and wear protective clothing in order from preventing the radiation to penetrate you?

2007-10-03 18:20:45 · 4 answers · asked by tara 2 in Medicine

This is my first time designing my own lab and was wondering if anyone has experience/knowledge on "Osmosis". I'm attempting to determine 'osmosis' in an egg by putting it in various solutions: honey, milk etc...

Anyways, would love to hear from you!

2007-10-03 18:18:05 · 5 answers · asked by Anonymous in Biology

F(z) = (1 + Z) / (1 - Z), where Z = x + iy

2007-10-03 18:17:39 · 3 answers · asked by frostwizrd 2 in Mathematics

"The results of the telepathic experiments carefully and plainly set forth in this book standly surely far beyond those which a nature investigator holds to be thinkable. On the other hand, it is out of the question in the case of so conscientious an observer and writer as Upton Sinclair that he is carrying on a conscious deception of the reading world; his good faith and dependability are not to be doubted. So if somehow the facts here set forth rest not upon telepathy, but upon some unconscious hypnotic influence from person to person, this also would be of high psychological interest." (Preface by Albert Einstein to Mental Radio by Upton Sinclair)

This sounds to me like Einstein is endorsing the study of parapsychology and finds Sinclairs work worthwhile.

2007-10-03 18:16:10 · 11 answers · asked by psiexploration 7 in Other - Alternative

Is there a highly productive and effecient way to chemically react something wth CO2 to make it managable and possible solid?

2007-10-03 18:14:54 · 2 answers · asked by Anonymous in Chemistry

The cubic polynomial f(x) is such that the coefficient of x^3 is 1 and the roots of f(x) = 0 are 1, k and k^2. It is given that f(x) has a remainder of 7 when divided by x - 2.

(i) Show that k^3 - 2k^2 - 2k - 3 = 0

(ii) Hence find a value for k and show that there are no other real values of k which satisfy this equation.

Please help me...I really really have no idea on how to do...

2007-10-03 18:11:07 · 5 answers · asked by ♪£yricảl♪ 4 in Mathematics

Alright this question uses the same exact formula, except both answers didn't explain the formula completely...

Here is the formula from my last question
"Formula for distance covered, s, is
s = ut + (1/2)at^2, where u = initial velocity and a = acceleration.
Here, u = 0 and a = 1.8 m/s^2
So, s = 0 + (1/2)(1.8)(1^2)
= 0.9 m."

^***What is the (1/2) for?***^

Here is the VERY similar question:

"A child slides down a hill on a toboggan with an acceleration of 1.8 m/s^2.

If she starts at rest, how far has she traveled in 2.0 s?"

So this is what I'd think you would plug in for the function

0 + (1/2)(1.8)(2^2), but it isn't correct and I still don't know what the (1/2) is.

2007-10-03 18:09:28 · 1 answers · asked by Anonymous in Physics