Science & Mathematics - 25 October 2006

As far as I understand it, in the mantle there is radioactive uranium mixed in with all of the other elements that make up the liquid rock down there. When this is spewed out onto the surface the breakdown of the uranium into lead that occurs happens at a standard half life rate and from the amount of breakdown we can work out how old the rock is. I have a couple questions about the intricasies of this.
1 - I heard that radioactive breakdown occurs in the mantle and that's why it's still hot, so wouldn't the ratio of Uranium and lead in the rocks that are spewed out by volcanoes change over time?
2 - What about regional differences within the magma?
Cheers

2006-10-25 02:57:13 · 6 answers · asked by schming2005 1 in Earth Sciences & Geology

how does ATP produce energy for cells????

2006-10-25 02:55:59 · 4 answers · asked by Ray 2 in Biology

A 37.7mL volume of an unknown gas is collected over water at 19 degrees C and a total pressure of 770 torr. The mass of the gas is 68.6mg.

2006-10-25 02:54:29 · 4 answers · asked by sarah jean 1 in Chemistry

could some1 pls tell me wat the social and economic advantages and disadvantages are of cloning and transplanting cattle emrbyos. Also what ethical issues does this create

thanks in advance

2006-10-25 02:53:07 · 2 answers · asked by Nick 3 in Biology

2006-10-25 02:51:20 · 5 answers · asked by Anonymous in Chemistry

2006-10-25 02:50:59 · 3 answers · asked by Dennis B 1 in Mathematics

Scientists informing us Big Bang theory for creation of thousands of universe from one burning object initially. which created sun,moon,planets, stars,comets.

2006-10-25 02:50:40 · 20 answers · asked by Anonymous in Astronomy & Space

2006-10-25 02:49:16 · 3 answers · asked by Anonymous in Engineering

what would be the derivative of

V=(1/3) pi h^2 (3R-h)


thanks

2006-10-25 02:48:30 · 5 answers · asked by leksa27 2 in Mathematics

currently finishing a PhD in biological sciences and would like to get out of academia into something well paid with job stabilty. Not sure where to look except jobs.ac.uk and newscientist. Would be interested in industry (pharmaceuticals/ biotechnology)- but don't know where to look/ how to apply at postdoc level, government (applying for civil service currently) or anything else I can use my qualifications for?

2006-10-25 02:48:06 · 8 answers · asked by Andrew H 1 in Biology

2006-10-25 02:47:08 · 2 answers · asked by J A 1 in Earth Sciences & Geology

How many acres are there on the moon?

2006-10-25 02:42:32 · 9 answers · asked by areyou_looking_atme 2 in Astronomy & Space

gimmie answer

2006-10-25 02:41:31 · 5 answers · asked by darigrlfrnd 2 in Other - Science

and I turn on the headlights the same instance I pass by someone outside the train...
I'm guessing the light travels away from me at the speed of light...
Does the light travel away from the person outside the train at double the speed of light, or is the light non existant to them since I'm stopped in time and the train is already moving away from them as fast as anything can travel.

2006-10-25 02:37:58 · 7 answers · asked by PS 4 in Astronomy & Space

My son wants to do his science fair project on the effect of different carbonated and non-carbonated beverages on bone density, as represented by some form of calcium. Pure calcium metal won't work and we don't want to use Tums. Calcium Hydroxyapatite would probably be the best, since that's the form calcium takes in the human body. But I only see it available in pill form. Is there a way to get bigger portions of it to make the tests easier, or is there some other form of Calcium that would work better?

2006-10-25 02:36:41 · 3 answers · asked by peteckart 1 in Chemistry

1.is the energy from tidal power used reguraly?
2.what do we use tidal power for?

2006-10-25 02:35:18 · 5 answers · asked by ryan f 1 in Earth Sciences & Geology

In a roomm with air at 20 deg. celcius, two cups are placed containing equal amounts of coffee but at 85 deg. celcius and 45 deg celius respectively. Coffee in the first cup cools down to 75 deg. celcius in 2 minutes. How long it will take for the coffee in the second cup to cool down to 35 deg. celcius.

2006-10-25 02:34:01 · 4 answers · asked by vijay kumar98724 1 in Physics

2006-10-25 02:33:14 · 7 answers · asked by Ranjith K 1 in Other - Science

2006-10-25 02:29:53 · 3 answers · asked by Ranjith K 1 in Other - Science

A wall of 0.5m thickness is to be constructed from a material which has an average thermal conductivity of 1.4W/m-K. This wall is to be insulated from outside with a material having an average thermal conductivity of 0.35W/m-K so that the heat loss per square meter will not exceed 1450W.Assuming that the inner & outer temperatures are 1200 deg.celcius and 15 deg. celcius respectively, calculate the thickness of insulation required.Also find the temperature of the wall-insulation interface.

2006-10-25 02:26:26 · 2 answers · asked by vijay kumar98724 1 in Physics

was just wondering.

2006-10-25 02:23:48 · 15 answers · asked by idril3lansar 1 in Zoology

2006-10-25 02:20:45 · 17 answers · asked by B. J. 4 in Geography

Say the effects of it. causes ofit. remeady of it.

2006-10-25 02:17:41 · 10 answers · asked by RED RANGER 2 in Earth Sciences & Geology

Ok..i have to do this science fair project and i have to know how to grow Bacteria! So i need help on knowing how to do this! If i need to buy certain things i would also appriciate it if you would give me a name of a place to where i can find these certain items or a web site where i can order them or somthing. Well thank you for your time!

2006-10-25 02:16:29 · 9 answers · asked by jojofantic 1 in Other - Science

2006-10-25 02:13:26 · 4 answers · asked by Anonymous in Mathematics

I am interested in that, "what is a black matter in the space?".

2006-10-25 02:12:31 · 2 answers · asked by Anonymous in Astronomy & Space

2006-10-25 02:12:12 · 5 answers · asked by reginal b 1 in Chemistry

2006-10-25 02:11:04 · 2 answers · asked by ishtiaq h 1 in Botany

2006-10-25 02:10:44 · 17 answers · asked by lexish.2006 1 in Weather

Obviously there is no reason to run one empty, but I've always been told that its a really bad thing to do... why?

2006-10-25 02:08:33 · 16 answers · asked by hardcoredjbenzy 3 in Other - Science