Science & Mathematics - 31 October 2007

3 questins; when looking at the periodic table how do you know if an element has any isotopes? what is a half-life element and how does it relate to isotopes? how is radioactivity released in an isotope?? need help with these!!

2007-10-31 01:49:33 · 3 answers · asked by ~~#1 cowgirl~~ 2 in Chemistry

A ball is projected horizontally from the top of a building. One second later, another ball is projected horizontally from the same point with the same velocity. At what point in the motion will the balls be closest to each other?
Will the first ball always be traveling faster than the second ball?
yes
no

What will be the time difference between them when the balls hit the ground?
no time difference
between one and ten seconds
one second
it depends on the height of the building

Can the horizontal projection velocity of the second ball be changed so that the balls arrive at the ground at the same time?
yes
no
Explain.

2007-10-31 01:45:49 · 3 answers · asked by wmartine 1 in Physics

The Illiniwek, was an indigenous people of Algonquian tribes that thrived along the Illinois River ultimately contributing the state's name. What meaning does the word "Illiniwek" have?

2007-10-31 01:44:11 · 2 answers · asked by daniel c 1 in Geography

I have this one problem I do not get at all.

"A 0.1153 gram sample of a pure hydrocarbon was burned in a C-H combustion train to produce 0.3986 gram of CO2 and 0.0578 gram of H2O. Determine the masses of C and H in the sample and the percentages of these elements in the hydrocarbon."

Please also show workings so I understand it! Thanks. Best answer will be chosen ASAP.

2007-10-31 01:37:13 · 3 answers · asked by onlineworld 1 in Chemistry

a. (0,2)
b. (2,0)
c. (-2,0)
d. (0, -2)

2007-10-31 01:35:54 · 3 answers · asked by Anonymous in Mathematics

very catchy blog name for a female woman..

2007-10-31 01:33:05 · 1 answers · asked by Anonymous in Other - Science

Rating=10W and Relative speed of flow = .Half as as 5W oil and second Rating=15W and..... Relative speed of flow = .Half as fast as 10W oil...........and third Rating =20W and Relative speed of flow= Half as fast as 15W oil.........According to the table above,car engine oil with a rating of 5W flows how many times as fast as car engine oil with a rating of 20W?please explain in detail.

2007-10-31 01:31:23 · 4 answers · asked by amjad 1 in Physics

2007-10-31 01:28:49 · 3 answers · asked by Anonymous in Other - Science

CFD has been used to conduct heat transfer studies on microfluids. Can this be extended to nanofluids???

2007-10-31 01:28:45 · 1 answers · asked by Anonymous in Engineering

I'm trying to figure out this proof for my exam later today and my professor and the assigned book are of little help... Any help from anyone out there would be great! Thanks in advance!

Prove that

rad <= diam <= 2*rad

(radius is less than or equal to diameter which is less than or equal to 2 times the radius)

2007-10-31 01:27:11 · 5 answers · asked by Keith 3 in Mathematics

2007-10-31 01:23:49 · 4 answers · asked by Anonymous in Earth Sciences & Geology

2007-10-31 01:23:17 · 4 answers · asked by Anonymous in Mathematics

2007-10-31 01:21:14 · 4 answers · asked by Anonymous in Mathematics

2007-10-31 01:16:03 · 6 answers · asked by letstalkbuiz 1 in Mathematics

I cannot get these problems.

1. The volume of a cuboid is 1536m^3. Its length is 16m and its breadth and height are in ratio 3:2. Find the breadth and height of the cuboid.

2. The surface area of a cuboid is 758cm^2. Its length and breadth are 14cm and 11cm. Find the breadth and height.

2007-10-31 01:15:39 · 4 answers · asked by ABHISHEK M 2 in Mathematics

Homework help. :]
Thanks.

2007-10-31 01:10:29 · 3 answers · asked by Anonymous in Geography

2007-10-31 01:09:54 · 3 answers · asked by suppajam 2 in Physics

tell me how you do it... in detail!

2007-10-31 01:08:48 · 6 answers · asked by Anonymous in Mathematics

2007-10-31 01:04:52 · 4 answers · asked by Salman K 1 in Weather

how do you factor

2007-10-31 00:57:27 · 5 answers · asked by lilcarrollw 2 in Mathematics

What are the adaptations of animals and plants that live in water, hot climate and cold climate. PLEASE HELP.....

2007-10-31 00:42:51 · 3 answers · asked by john 2 in Zoology

I read an article in Wired magazine the other day which advocated scientists start referring to evolution as a law rather than a theory.

The idea was that theists and supporters of intelligent design have seized on the phrase "theory of evolution" to indicate that scientists are not confident in the idea. They use a layman's definition of theory which mean something you think but can't really prove. However, when a scientist uses the word theory, they often mean something that would be more equivalent to the layman's definition of law.

2007-10-31 00:39:53 · 6 answers · asked by Justin H 7 in Biology

Aspergillus niger is a type of fungi. it's cell wall is made up of chitin. these chitin wall have N-acetyl glucosamine linkages.so, how to break chitin wall &get the enzyme-Glucose oxidase.

2007-10-31 00:36:55 · 2 answers · asked by Anonymous in Biology

For an assignment, I haven't gotten around to asking people.

Which of the following statements do you think is most correct, regarding evolution?
• Evolution is the greatest myth of the 20th century. It has no really hard evidence to support it
• Evolution is a fact. Everyone knows that humans evolved from apes.
• Evolution is all about adapting. When the environment changes a species will adapt and evolve to cope with their changed surroundings.
• Evolution is descent with modification via the process of natural selection.
• Evolution is organisms changing themselves to perfection

Thanks all

2007-10-31 00:36:33 · 12 answers · asked by Anonymous in Biology

drink...
colour (im not American...)
type of food
position in bed
Type of music
skin care

And also
where do I live?

2007-10-31 00:31:36 · 8 answers · asked by Anonymous in Parapsychology

I am a firstly experienced guy in this kind of buying. I would appreciate comments only from very experienced buyers.

2007-10-31 00:30:50 · 1 answers · asked by Anonymous in Other - Science

I've heard some chilling storied about ghosts, even a couple about possessions, UFO's etc. Anything else you want to share is fine too, I'm just curious.

Honestly, I had an experience when I was young that part of me wants to blame on a ghost, but I am huge skeptic. What do you think? No one please insult the beliefs or feelings of others here, let's respect what each other have to say.

2007-10-31 00:25:31 · 11 answers · asked by Anonymous in Paranormal Phenomena

2007-10-31 00:18:27 · 17 answers · asked by timelord 1 in Physics

2007-10-31 00:09:17 · 6 answers · asked by Anonymous in Botany