Science & Mathematics - 27 September 2007

could someone tell me the exact chemical names of Mn2O3, MnO2, MnO3 and Mn2O7, eg: manganese (II) oxide, i got manganese (II) oxide for all of them! CLEARLY WRONG!
An explanation would be good,

thank you very much

2007-09-27 06:39:15 · 3 answers · asked by Anonymous in Chemistry

A stopper was found to have a mass of 5.06g. When placed in a graduated cylinder containing 45.2mL of water, the volume of the stopper was found to be 49.4mL. What is the density of the stopper?

2007-09-27 06:38:48 · 4 answers · asked by furikuri405 1 in Chemistry

(I am not suggesting it isn't by the way)

And we accept the Theory of evolution as correct.. does it not stand to reason that there is an evolutionary purpose for it. I mean it is too prolific amongsst the specied to simply be a rogue genetic mutation.

What could some of those reasons be?

Please just because the subject is a little delicate in modern society please try to respond rationally.

2007-09-27 06:38:13 · 27 answers · asked by Wayne Kerr 3 in Biology

A box has a rectangular base of 30cm by 25cm. Iron rods are to be placed in the box.
a.) Calulate the biggest sized rod that could be laid down in the box.
b.) Only one rod is to be placed in the box. Calculate the longest rod possible that can be placed in the box.

Answers:
a.) 39.05
b.) 41.83
But, how do you get thoose answers???

2007-09-27 06:36:53 · 9 answers · asked by youlookingood 1 in Mathematics

Or is it just another theory made up by some wacky scientists?

2007-09-27 06:31:02 · 6 answers · asked by Anonymous in Physics

What happens when you place sodium ethanoate powder in dilute hydrochloric acid and warm the mixture?

I would also appreciate any equations (or reaction mechanism if applicable)

2007-09-27 06:28:16 · 2 answers · asked by H 1 in Chemistry

Is the contraction of objects traveling at very high speeds real, or is it juast a optical phenomenon, an ilusion? Why does it happen? What do pepole actually know about it until now? was it proved through experiments, like time dilation, or is it just a completely theoretical thing?

It seems pretty normal to me that we percive objects traveling at high speeds longer, but that's just the eye fooling us, and it's got mothing to do with phizics.

2007-09-27 06:26:07 · 4 answers · asked by vlad r 3 in Physics

int (root(4 - x^2)) = ?

I know the answer involves arcsin somehow but have no idea how to get there, im a bit rusty at these and would appreciate the method used as well as the answer

2007-09-27 06:26:03 · 6 answers · asked by ultimaninjabob 1 in Mathematics

6. The ability of an organism to maintain constant conditions within its body is called __________.
A. homeostasis
B. reproduction
C. response
D. development

7. The process of passing genetic information on to an organism's offspring is _________.
A. metabolism
B. homeostasis
C. heredity
D. chromosome

8. The smallest units that retain the chemical properties of the element from which they come are _________.
A. atoms
B. electrons
C. molecules
D. protons

9. All matter in the universe is composed of _________.
A. cells
B. molecules
C. atoms
D. carbon

10. All living things __________.
A. are composed of at least one cell
B. respond to their environment
C. use and obtain energy
D. all of the above

11. Sharing of electrons in the outer energy levels of two atoms __________.
A. results in ion formation
B. occurs in covalent bonds
C. occurs in ionic bonds
D. None o

2007-09-27 06:22:23 · 3 answers · asked by Anonymous in Other - Science

2007-09-27 06:18:56 · 20 answers · asked by Anonymous in Astronomy & Space

2007-09-27 06:16:17 · 2 answers · asked by Flashing Lights 2 in Chemistry

Acidification of sodium bicarbonate (NaHCO3) produces carbon dioxide in a two step process.

The first step produces carbonic acid (H2CO3). Write and balance the molecular equation for the first step of the reaction of sodium bicarbonate with HClO4. (Do not include symbols for state of matter in your answer).

The second step is the decomposition of carbonic acid to carbon dioxide. Write and balance the molecular equation for the second step.

Now write the overall net ionic equation for the acidification of NaHCO3 to produce CO2.

What is the molar ratio of CO2 produced to NaHCO3 decomposed?
What mass of CO2 will be produced by the complete decomposition of 1156 mg of NaHCO3?

Thank you for any help.

2007-09-27 06:14:49 · 1 answers · asked by Anonymous in Chemistry

Determine the structure of Benzene, and important organic compound, proved to be a difficult challenge for chemists in the 19th century. A sample of benzene was analyzed and found to consist of 1.43g of carbon and 0.119g of hydrogen. Given that the molar mass of benzene is 78.0g, determine both the empirical formula and the molecular formula for benzene.

2007-09-27 06:10:42 · 3 answers · asked by Craig x 1 in Chemistry

Suppose you take a state machine(a machine who's output is dependant on its inputs and the internal state of the machine) and take the dimension of time and turn it into a 4th spacial dimension, would we then have a 4 dimensional combinational machine(a machine whos outputs are only dependant on its inputs)?

2007-09-27 06:10:13 · 2 answers · asked by LG 7 in Physics

someone please help me I've been trying to figure this out for days now.. I'm trying to help my son with his math homework and I want to make sure I have the right answer but I ca't figure it out



Solve for the value of y and the measures of angles 1 and 3. Please show work. One of the lines crosses another line to form four angles labeled clockwise 1,2,3, and 4. The measures of these angles are:
(angle 1)M<1 = (6y +29)
(angle 2)M<2 = (4x+31)
(angle 3)M<3 = (1 2y -7)
(angle 4)M<4 = (6x - 11 )

2007-09-27 06:08:21 · 9 answers · asked by Jenn H 1 in Mathematics

2007-09-27 06:07:17 · 7 answers · asked by Anonymous in Zoology

I have seen black widow spiders in my garage, but I found a very odd spider that was the shape of a black widow it had a red hourglass, but it was striped. It was not very big only about the size of my pinkie nail what is it do you think? Are there different variations of the Black widow spider or is it a possible mutation?

2007-09-27 06:07:17 · 3 answers · asked by Vivianna 4 in Zoology

2007-09-27 05:59:50 · 11 answers · asked by Anonymous in Mathematics

2007-09-27 05:56:48 · 23 answers · asked by chloe 1 in Engineering

2007-09-27 05:54:56 · 8 answers · asked by Anonymous in Astronomy & Space

I can't seem to find any information on this in the book, nor do I feel like I really understand the concept. Any help would be greatly appreciated!!!

1. Block m1 has a mass of 4 kg and m2 has a mass of 2 kg. The coefficient of kinetic friction between m2 and the horizontal plane is 0.5. The incline plane is frictionless. The angle of the incline plane is 30 degrees.
a) Calculate the tension in the cord.
b) Calculate the acceleration of the blocks.

2007-09-27 05:54:29 · 4 answers · asked by soliel021 3 in Physics

2007-09-27 05:51:38 · 30 answers · asked by Trell A 1 in Mathematics

please, only serious answers and please don't say ask a doctor or check the bottle. thanks you.

2007-09-27 05:49:27 · 7 answers · asked by elite mobile 2 in Medicine

About cones (math)
let a=cone angle at tip
s=sin(a/2 * pi/180)
d='diameter multiplier'
w=wedge cut out from circle (degrees)
d=1/s
w=s*360

2007-09-27 05:47:27 · 2 answers · asked by Anonymous in Mathematics

Why is Acetic Acid's molar mass twice what it should be when in CCl4 or benzene solution?

Can someone explain why this ocurres?

2007-09-27 05:47:13 · 1 answers · asked by Carolina 4 in Chemistry

Solve

2007-09-27 05:47:01 · 9 answers · asked by shawntae6513 1 in Mathematics

18. in going from right to left in any given row in the periodic table, the size of atoms generally __.
A. increases B. decreases C. stays the same D. changes randomly

19. compared to the neutral atom from which it is derived, a negative ion is __.
A. always larger B. always smaller C. larger in some cases and smaller in others D. the same size

20. transition elements, such as chromium, are likely to have __.
A. an oxidation number of 1+
B. an oxidation number of 2+
C. multiple oxidation numbers
D. a negative oxidation number

21. a metallic ion is __ its corresponding atom.
A. larger than
B. smaller than
C. the same size
D. impossible to compare with

22. ionic radii __ down a group in the periodic table.
A. increase B. decrease C. stay the same D. follow no pattern

23.alkaline earth metals lose __ electrons to achieve the electron configuration of the noble gas in the preceding period.
A. one B. two C. six D. seven

2007-09-27 05:36:38 · 2 answers · asked by Anonymous in Chemistry

Need help

1.The intersection of two planes could be which of the following:

A) a ray
B) a segment
C) a line
D) a point

2. Find the midpoint between the points (2,-4) and (5,-2).

A) (-1,1.5)
B) (3,3.5)
C) (3.5,-3)
D) (-1.5,-1)

2007-09-27 05:34:41 · 8 answers · asked by Anonymous in Mathematics

2007-09-27 05:31:52 · 20 answers · asked by madnsane 2 in Astronomy & Space

11. an element is in group 15. the last electron added to an atom of this element will be in a(n) __ sublevel.
A. s B. p C. d D. f

12. an atom is in group 2, period 3. how many electrons does the atom contain?
A. 2 B. 3 C. 5 D. 12

13. which is a possible last sublevel for an element found in group 18?
A. 3p6 B. 4s2 C. 4p3 D. 4d8

14. an element is most likely to have properties similar to those of __.
A. another element in the same period
B. another element in the same group
C. a noble gas
D. a transition element

15. transition elements have final electrons in the __ sublevel.
A. s B. p C. d D. f

16. what are the valence electrons in the electron configuration of tin, [Kr] 4d105s25p2?
A. [Kr] B. 4d10 C. 5s25p2 D. 5p2

17. each row in the periodic table ends with a __.
A. metal B. nonmetal C. metalloid D. noble gas

2007-09-27 05:31:35 · 1 answers · asked by Anonymous in Chemistry