Science & Mathematics - 18 June 2006

Does it really help you stay drier or is the amount of rain hitting you the same (since you're running into raindrops in addition to them landing on your head)?

2006-06-18 04:09:37 · 11 answers · asked by Anonymous in Other - Science

i have a 500 gallon tank of water connected to my travel trailer. It looks like it has algae in it.

2006-06-18 04:09:23 · 2 answers · asked by MAMOU 1 in Chemistry

"twice the product of two consecutive integers"
i dont get it..

2006-06-18 04:02:54 · 8 answers · asked by aNgeLa_kriz 2 in Mathematics

2006-06-18 03:59:48 · 5 answers · asked by boyrambo 1 in Astronomy & Space

If mankind finds a Earthlike planet and we send people there. How will we deal with the poeple of that planet if they are...
less intellagent than us?.....
more intellagetn than us?.....
Indeginouse people have always been tricked out of their land or they have been killed off. Will mankind repeat history and kill off the aliens? Do governments have a set standered of conduct? Or is that only on Star Trek?

2006-06-18 03:57:56 · 12 answers · asked by crossbones59 1 in Earth Sciences & Geology

With the equations of:
a^2 + b^2 = d^2
b^2 + c^2 = e^2
a^2 + c^2 = f^2 and
a^2 + b^2 + c^2 = g^2
with all variables being intergers,
wouldn't it seem more logical to have all even sides?

2006-06-18 03:56:56 · 1 answers · asked by freemanbac 5 in Mathematics

2006-06-18 03:55:01 · 12 answers · asked by Anne2663 1 in Astronomy & Space

2006-06-18 03:48:57 · 5 answers · asked by NEOTEH 4 in Chemistry

Nanotech news November 16th, 1998

Good news from the Sixth Foresignt Conference in Santa Clara.
Five major advances were announced. Here is a brief summary of each advance:

1 - Bucky Horns: Sumio Iijima of NEC Corporation, Japan, announced the ability to grow this new class of carbon nanostructures, the next step beyond buckyballs and buckytubes.

2 - Biopowered Nanomotor: Carlo Montemagno of Cornell University announced success in building biological-motor powered mechanical devices. All the tools are now in place to make this happen within a living cell.

3 - Nanomanipulator: MinFeng Yu of Washington University generated excitement by showing the first-ever movies of interactive 3D manipulation of carbon nanotubes, using a new research device built by Zyvex LLC.

4 - Nanotube Transistor: Cees Dekker of Delft University of Technology, The Netherlands, presented work on buckytubes as a
new kind of molecular quantum wire and a field effect nanotube transistor, called TubeFET.

5 - Single-Molecule Tape Measure: Mark Akeson of University of California, Santa Cruz, announced the use of a molecular pore able to electrically "read" long molecules at high speed, even differentiating among DNA bases in groups as small as five. Next goal: rapidly read DNA base-by-base

2006-06-18 03:45:03 · 7 answers · asked by <•>U4IK ST8<•> 2 in Other - Science

Why? And why can a human die anytime in his/her life. How can a human die. How can a human live his/her life knowing that he/she going to die. How do a human live everyday.

2006-06-18 03:44:36 · 26 answers · asked by will_jones_90 3 in Biology

2006-06-18 03:44:26 · 15 answers · asked by Corazon R 1 in Other - Science

2006-06-18 03:42:03 · 10 answers · asked by NEOTEH 4 in Chemistry

2006-06-18 03:35:31 · 11 answers · asked by viraj l 1 in Astronomy & Space

I hear we're all made out of supernova is that true?

2006-06-18 03:30:07 · 11 answers · asked by Anonymous in Astronomy & Space

Just for fun.

2006-06-18 03:30:04 · 14 answers · asked by Keyofsee 1 in Physics

2006-06-18 03:22:00 · 7 answers · asked by joey01_maggot k 1 in Geography

In an arguement about animals or cars supporting people which is better for the environment. I wish to show that while carbon monoxide is a posin it is actually better than the number of animals needed to support our live style.

2006-06-18 03:17:29 · 9 answers · asked by mechunka1 1 in Chemistry

There is an electrical source kind of close (maybe 500-1000) feet from my study site. I need power in my study site. Can an extension cord handle ~1500 watts of power at this distance. Is it unsafe to run them this long?

2006-06-18 03:07:32 · 5 answers · asked by brandonbarton1981 2 in Engineering

2006-06-18 03:05:38 · 13 answers · asked by Goddix 1 in Mathematics

2006-06-18 02:56:35 · 5 answers · asked by KIM C 1 in Biology

tempature was approx 90 deg. F

2006-06-18 02:56:17 · 2 answers · asked by dan j 1 in Physics

1. Which of the following solids consists of atoms or molecules held together only by Van Der Waals forces?
1



a.
carbon dioxide




b.
water




c.
silicon dioxide




d.
copper





2. What is the approximate value of the O-C=O bond angle in ethanoic acid?
1



a.
45 degrees




b.
90 degrees




c.
120 degrees




d.
180 degrees





3. Which of the following does NOT contain hydrogen bonds?
1



a.
Ammonium chloride




b.
Ammonia




c.
Nitric acid




d.
Water





4. In microwave ovens, the wave energy produced is absorbed by certain polar molecules.
Which of the following would absorb microwave energy?
1



a.
Aluminium trichloride




b.
Carbon dioxide




c.
Ethanol




d.
Sodium chloride





5. The grid represents two periods of the Periodic Table, for the elements with proton number from 3 to 18:






P





Q



R


S



An element from 1 group, P, Q, R or S, reacts with an element from another of these groups to produce a compound with a giant covalent structure.
Which are these 2 groups?
1



a.
P and R




b.
Q and R




c.
Q and S




d.
R and S





6. Graphite can be used as a lubricant; diamond cannot. This is because graphite has
1



a.
Mobile ions




b.
A hexagonal arrangement of atoms in the layers




c.
Van Der Waals forces between the layers of atoms




d.
Covalent bonds between atoms in the layers





7. 109.5°

107°

105°

0.096 nm

0.101 nm

0.109 nm

The bond lengths and bond angles in the molecules of methane, ammonia and water may be represented as follows:

What causes this trend in bond angles shown?
1



a.
Increasing repulsion between hydrogen atoms as the bond length decreases




b.
The number of bonding electron pairs in the molecule




c.
A non-bonding electron pair having a lower repulsive force than a bonding electron pair




d.
The number of non-bonding electron pairs in the molecule





8. Which type of bond is responsible for intermolecular forces in liquid tetrachloromethane?
1



a.
Covalent bonding




b.
Hydrogen bonding




c.
Temporary dipole-induced dipole attractions




d.
Permanent dipole-permanent dipole attractions





9. A solution of ammonia in water contains
1



a.
Simple molecules only




b.
Simple molecules and hydrogen bonded molecules only




c.
Simple molecules, hydrogen bonded molecules and ions




d.
Ions only





10. The diagram below shows a liquid flowing from a burette and a charged rod being brought near the flow.

Which liquid would be deflected as shown?
1



a.
Bromine




b.
Hexachloroethane




c.
Cyclohexane




d.
Trichloromethane





11. In which one of the following does ionic bonding occur between the named atoms?
1



a.
Aluminium and chlorine in tetrachloroaluminate ion




b.
Boron and fluorine in boron trifluoride




c.
Hydrogen and chlorine in hydrogen chloride




d.
Hydrogen and sodium in sodium hydride





12. The radius and charge of each of 6 ions are shown in the table below:

Ion
J+
L+
M2+
X-
Y-
Z2-

Radius/nm
0.14
0.18
0.15
0.14
0.18
0.15


The ionic solids JX, LY and MZ are of the same lattice type.

What is the correct order of their lattice energies placing the one with the highest numerical value first?
1



a.
JX > LY > MZ




b.
JX > MZ > LY




c.
LY > MZ >JX




d.
MZ > JX > LY





13. Silicon carbide is a shiny, hard, chemically inert material with a very high melting point. It can be used to sharpen knives and make crucibles. Which type of structure explains these properties?
1



a.
A giant structure with covalent bonds between silicon and carbon atoms




b.
A giant structure containing metallic bonding




c.
A giant layer structure with covalent bonds between atoms and Van Der Waals forces between the layers




d.
A simple molecular structure with covalent bonds between atoms of silicon and carbon











14. A stable molecule containing atoms of the elements X, Y and Z has the following structure:

Which elements could X, Y and Z be?
1



a.
X=N, Y=P, Z=Cl




b.
X=O, Y=S, Z=Cl




c.
X=B, Y=C, Z=H




d.
X=P, Y=Si, Z=H


15. Which one of the following sets of solid elements A, B, C or D includes a giant metallic structure, a macromolecular structure and a simple molecular structure? 1
a. Na Mg Al
b. Mg Al Si
c. C Si Sn
d. Al Si S
16. Which of the following is an example of a substance with a macromolecular structure? 1
a. Aluminium chloride
b. Ice
c. Magnesium oxide
d. Silicon dioxide
17. The molecules listed below are of the general formula XYn, with n more than or equal to 2. In which is the Y-X-Y angle greatest? 1
a. BF3
b. CH4
c. NH3
d. PCl3



18. The sulphite ion may be represented as:

What is the O-S-O bond angle?
1



a.
About 90 degrees




b.
About 107 degrees




c.
About 109.5 degrees




d.
About 117.5 degrees


19. Which of the following statements about the properties associated with ionic and covalent bonds is correct? 1
a. A covalent bond cannot be an electrolyte.
b. The only covalent compounds with high melting points are those in which hydrogen bonds occur.
c. Ionic bonds and covalent bonds cannot both occur in the same compound.
d. Ionic compounds differ from metals in that ionic compounds do not conduct electricity in the solid state



20. Cleavage readily occurs along planes of crystals of ionic solids because the ions in the crystal are 1
a. Arranged in a regular fashion
b. Strongly bonded together
c. Weakly bonded together
d. Charged

2006-06-18 02:52:46 · 5 answers · asked by Professor X 1 in Chemistry

I know it would be almost infinitely unlikely, but wouldn't it be technically possible to have twins that are both identical and fraternal? I.e., they come from different eggs but coincidentally have the same DNA?

2006-06-18 02:48:39 · 9 answers · asked by . 3 in Biology

2006-06-18 02:48:27 · 12 answers · asked by audj817 1 in Mathematics

coporate greed is dangerous for american freedoms especially when it and the american government are the same when it ideas of individual freedoms and rights do not exist.This is a reminder to the american people individual built this country not corporate america.I have develop technology above all others governements a machine that control all physical motion no missle,jet fighters will have chance soon from this technology a energy sheild.If you do not believe me ask the people in Live oak ,jasper lake city florida and others when you feel you car being pull left or right .I am looking for a non coprorate partner to develop technology to its full capablities post e-mail for contact.

2006-06-18 02:48:18 · 1 answers · asked by kelvin_lee45 1 in Physics

2006-06-18 02:45:41 · 4 answers · asked by Shinjin 1 in Other - Science

2006-06-18 02:37:37 · 8 answers · asked by zplumber2000 1 in Astronomy & Space

Can you think of a really good science fair project for someone in the 9th grade?

2006-06-18 02:33:08 · 18 answers · asked by weatherfield12 2 in Other - Science

My friend's 12 year old sister has a friend who has blond hair and blue eyes. Her mother is Korean. I didn't think that this is possible, because blond hair, blue eyes is recessive, and I'm pretty sure that these genes aren't found in the Korean population. Now the mother could be half Korean (my friend wasn't sure), which would make the blond haired, blue eyed child possible. But for the sake of this question, I'm assuming the mother is full Korean, and the kid wasn't adopted.

2006-06-18 02:32:19 · 14 answers · asked by thedivineoomba 5 in Biology

we have an assignment, we are asked about why do some people die with their eyes open? what could be the medical explanation of that? please.. i need thte answer.

2006-06-18 02:30:29 · 7 answers · asked by Anonymous in Medicine