Science & Mathematics - 26 September 2006

Silicon has 3 common isotopes 28 Si, 29 Si and 30 Si. the number is the atomic mass. the average atomic mass of Si is 28.0855. determine the percent abundance for each isotope w/o looking it up.

i dont need the answer, just the method of determining it
i was planning on a system, w/ the equations being:
28x+29y+30z=28.085
x+y+z=1 The variables are percent abundance

However, i dont think this will work b/c i need a third equation.
if anyone knows how to do this, please answer with how and i will greatly appreciate it.

2006-09-26 15:11:03 · 2 answers · asked by George S 4 in Chemistry

i need an example of 6 non living things that contains one of each characteristics of living things.
1) is composed of cells
2) reproduce, grow and repair themselves
3) requires energy
4) responds to the environment
5) has a lifespan
6) produces waste

I'm really confused right now, i only got living things' answers

2006-09-26 15:10:42 · 5 answers · asked by imnbvcx2005 1 in Biology

In this link (it's just a picture), is an equation;

http://img.photobucket.com/albums/v638/ravenatic20/untitled1.jpg

Can you give a reason that justifies the equation, using the 6 general laws of arithmetic (assoc., dist., comm.) and the basic laws of fractions?

2006-09-26 15:10:41 · 3 answers · asked by Anonymous in Mathematics

When the homologous pairs line up, is it four separate chromatids that are lining up, and two go to each new cell? When you say that the homologous chromosomes separate, do they mean chromosome as in two chromatids or one?

2006-09-26 15:09:48 · 3 answers · asked by Kiko 3 in Biology

I was wondering, bcs i think i might be interested in that career.

2006-09-26 15:08:28 · 11 answers · asked by noooo 2 in Medicine

All the way to the core of the earth?

2006-09-26 15:07:39 · 5 answers · asked by Anonymous in Earth Sciences & Geology

my friend told me that pluto has been takin out of the listings as a planet.... is this true she said it was on the news??

2006-09-26 15:04:45 · 22 answers · asked by Anonymous in Astronomy & Space

Methane CH4, Aluminum Chloride AlCl3, Ethanol C2H5OH, Benzene C6H6, Copper Cu

2006-09-26 15:04:42 · 8 answers · asked by SICK MY DUCK! 1 in Chemistry

2006-09-26 15:00:01 · 13 answers · asked by Anonymous in Other - Science

2006-09-26 14:59:56 · 3 answers · asked by Anonymous in Earth Sciences & Geology

2006-09-26 14:59:16 · 6 answers · asked by SICK MY DUCK! 1 in Chemistry

2006-09-26 14:58:20 · 3 answers · asked by rastapopulous 1 in Other - Science

Where they launched two satellites with the most perfect gyroscopes ever built to measure if the earth's gravity affects spacetime (or something like that). Any clarifications on the experiment would be greatly appreciated.

2006-09-26 14:57:32 · 2 answers · asked by Anonymous in Astronomy & Space

2006-09-26 14:57:28 · 9 answers · asked by Anonymous in Earth Sciences & Geology

As a bus approaches a turn it goes from 30 m/s to 5 m/s in a space of 5 seconds. What was its acceleration?

2006-09-26 14:55:31 · 6 answers · asked by Helena 1 in Mathematics

THIS CHILD HAD A NORMAL BIRTH WEIGHT BUT UPON LEAVING FOR HOME,STOPPED BREATHING AND WAS DIAGNOSED WITH A BRAIN BLEED

2006-09-26 14:55:23 · 3 answers · asked by SEWER 1 in Medicine

Are those inexpensive Celestron telescopes worth the $110?

2006-09-26 14:52:52 · 8 answers · asked by WheeeeWhaaaaa 4 in Astronomy & Space

I need to prepare an enrichment culture of Methylobacterium mesophilicum. I just read online, that I should use methanol as my only carbon source.
The ingredients I had originally thought about where:
5g peptone, 3g meat extract, 15g agar, 1000ml water, 1% methanol. I was also going to add 10 mg of MnSO4 for sporulation

Does anyone know? Please help

2006-09-26 14:52:33 · 2 answers · asked by BeachGirl 3 in Biology

2006-09-26 14:52:31 · 6 answers · asked by Anonymous in Mathematics

i want to know if its possible

2006-09-26 14:52:22 · 4 answers · asked by GREGORIO G C 1 in Earth Sciences & Geology

lim x -> 5- e^x/(x-5)^3. I got oo.

2006-09-26 14:51:25 · 5 answers · asked by Anonymous in Mathematics

2006-09-26 14:51:04 · 3 answers · asked by Dwight D 1 in Biology

2006-09-26 14:49:13 · 4 answers · asked by Baralia 1 in Chemistry

2006-09-26 14:48:52 · 3 answers · asked by Anonymous in Chemistry

Prove if true.

2006-09-26 14:48:10 · 4 answers · asked by kuxuru 3 in Mathematics

two masses, m1 and m2, connected by a massless string, are accelerated uniformly on a frictionless surface. What is the ration of the tensions T1/T2.
I get an answer of m1/(m1+m2), but i am not sure if this is correct. Can you show me why this is correct?

Two masses, m1=12 kg and m2=35kg, are held connected by a massless rope hung over a frictionless light pulley. If the masses are released, what is the magnitude of the tension in the string.
My instructor says that the answer is 175N, but i don't get this answer. I get 225N. Why is this wrong. What i am doing is subtracting 12 from 35 and multpilying by 9.8. What is wrong with this?

Three blocks are connected by massless cords and rest on a frictionless horizontal surface. The blocks are pulled to the right. Mass m1=2, m2=3m3, with m1 on the left, and m3 on the right. IF the pulling force is equal to 90N, what is the tension in the cord between m1 and m2.

Why is the answer 49N?

2006-09-26 14:46:44 · 2 answers · asked by Anonymous in Physics

we saw something that was colored like a bumble bee but acted like a humming bird. it was black and yellow and only about 1-2" long. it was flying back and forth between a few flowers and i am 100% positive it wasn't a bee. this was in central ohio.. anyone know for sure what it was. i don't want guesses from people unless they have a good idea of what it is including a name. it would be nice for a reference of where i can look it up with a picture.

2006-09-26 14:45:55 · 11 answers · asked by valiantw2001 2 in Zoology

2006-09-26 14:44:27 · 6 answers · asked by mag c 1 in Mathematics

2006-09-26 14:41:21 · 5 answers · asked by Kelly D 2 in Other - Science

its derivatives of logarithmic functions

how do you find y ' if x^y = y^x

2006-09-26 14:41:06 · 6 answers · asked by softball579 1 in Mathematics