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DIAMOND: The gem stone is the "HARDEST MATERIAL" In "INDIA" each diamond is sp3 hybridisation and is linked to four carbon atoms by single covalent bonds. The are also known to be tetrahedrally. PROPERTIES: It has the highest m
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submitted by know_something111 (19 m) on 28 Jul 2007 21:14:23 IST (2 comments 95 views)
Graphically, a vector is represented by an arrow, defining the direction, and the length of the arrow defines the vector's magnitude. This is shown in Panel 1. . If we denote one end of the arrow by the origin O and the tip of the arrow by Q. Then the vector may be represented algebraically by OQ. Panel 1 This is often simplified to just . The line and arrow above the Q are there to indicate that the symbol represents a vector. Another notation is boldface type as: Q. Note, that since a direction is implied, . Even though their lengths are identical, their directions are exactly opposite, in fact OQ = -QO. The magnitude of a vector is denoted b
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submitted by nivedh_89 (4548 m) on 28 Jul 2007 12:09:36 IST (1 comments 137 views)
Keq, Kw and pH As H2O is the medium of biological systems one must consider the role of this molecule in the dissociation of ions from biological molecules. Water is essentially a neutral molecule but will ionize to a small degree. This can be described by a simple equilibrium equation: H2O <-------> H+ + OH- Eqn. 1 This equilibrium can be calculated as for any reaction: Keq = [H+][OH-]/[H2O] Eqn. 2
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submitted by nivedh_89 (4548 m) on 28 Jul 2007 10:03:55 IST (1 comments 129 views)
LOVE LETTER BY A MATHEMATICIANDe-Morgan's Law,Binomial Avenue,United States of Matrices.My Dear Love,Yesterday, I was passing by your rectangular house in trigonometriclane. There I saw you with your cute circular face, conical nose andspherical eyes, standing in your triangular garden. Before seeing you myheart was a null set, but when a vector of magnitude (likeness) from youreyes at a deviation of theta radians made a tangent to my heart, it differentiated.My love for you is a quadratic equation with real roots, which only youcan solve by making good binary relation with me. The cosine of my lovefor you extends to infinity. I promise that I should not resolve you
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submitted by a4asd (329 m) on 27 Jul 2007 14:42:02 IST (3 comments 113 views)
I was in the airport VIP lounge en route to Seattle a couple of weeks ago.While in there, I noticed Bill Gates sitting comfortably in the corner, enjoying a drink. I was meeting a very important client who was a! lso flying to Seattle , but she was running a little bit late.Well, being a straightforward kind of guy, I approached the Microsoft chairman, introduced myself, and said, "Mr. Gates, I wonder if you would do me a favor.""Yes?""I'm sitting right over there," pointing to my seat at the bar, and I' m waiting for a very important client. Would you be so kind when she arrives as to come walk by and just say "Hi Tom?""Sure."I shook his hand and thanked him and we
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submitted by manastalkinglive (0 m) on 27 Jul 2007 13:26:38 IST (3 comments 115 views)
Reactions Involving Aldehydes and Ketones Basically there are two kinds of reactions involving nucleophiles and acyl compounds: Nucleophilic Additions Nucleophilic Substitutions The factor that decides whether the acyl compound will undergo addition or substitution largely depends upon the ability for an atom attached to the acyl carbon to undergo heterolysis taking the bonding electrons with it as it leaves the acyl carbon having been displaced by the incoming nucleophile. Different atoms or groups of atoms will have different abilities to leave the acyl compound. The greater the "leaving group ability"(LGA) the more likely the acyl compound
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submitted by manastalkinglive (0 m) on 27 Jul 2007 13:50:57 IST (0 comments 82 views)
Aldehydes and Ketones. Reduction to Hydrocarbons (review of Chapter 12) Clemmensen Reduction (acidic conditions) Zn(Hg) in HCl reduced the C=O into-CH2- Wolff-Kishner Reduction (basic conditions) NH2NH2 / KOH / ethylene glycol (a high boiling solvent) reduces the C=O into -CH2- Overview These reduction methods do not reduce C=C, C?C or -CO2HThe choice of method should be made based on the tolerance of other functional groups to the acidic or basic reaction conditions.Reactions of RLi and RMgX with Aldehydes and Ketones Reactions usually in Et2O or THF f
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submitted by nivedh_89 (4548 m) on 27 Jul 2007 11:06:02 IST (0 comments 180 views)
The wave nature of the electron is what makes atoms have the properties that they do. It explains the colors of the atoms and also their size. It also means that we cannot think about the electron in an atom as a little ball whirling about the nucleus, but a cloud of probability that is smeared out over the orbit. This cloud is only spherical for the lowest energy level of the atom. As the energy of the electron in the atom increases, its wavelength decreases, and the number of times the wave amplitude crosses zero per orbit increases. Again, these zero crossings are called nodes. The number of nodes is related to the frequency of the wav
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submitted by nivedh_89 (4548 m) on 26 Jul 2007 10:00:46 IST (6 comments 570 views)
TEMPERATURE There are three main scales for measuring temperature: the Fahrenheit scale imperial), the Celsius scale (metric) and the absolute temperature scale (SI), which is measured in Kelvin. The absolute temperature scale is seen as the most scientific because 0 Kelvin (-273°C) is absolutely zero: the temperature at which no more heat can be extracted from an object. Scientific theory holds that this point of absolute cold would be impossible to reach in practice. Celsius(°C) Fahrenheit(°F) Kelvin(K) 110 230 383 100 212 373 90 194 363 80 176 353 70 158 343 60
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submitted by yazukastinger (203 m) on 26 Jul 2007 20:51:52 IST (0 comments 76 views)
RELATIVE DENSITY DEFINITION. Relative density or density index is the ratio of the difference between the void ratios of a cohesionless soil in its loosest state and existing natural state to the difference between its void ratio in the loosest and densest states. Where, emax = void ratio of coarse grained soil ( cohesionless) in its loosest state. emin = void ratio of coarse grained soil ( cohesionless) in its densest state. e = void ratio of
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submitted by yazukastinger (203 m) on 26 Jul 2007 20:45:40 IST (0 comments 60 views)
this is an intresting curve ,,,,,,one of tthe most beautiful in mathematics There are two curves known as the butterfly curve. The first is the sextic plane curve given by the implicit equation (1) (Cundy and Rollett 1989, p. 72; left figure). The total area of both wings is then given by (2) (3) (4) (Sloane's A118292). The arc length is (5) (Sloane's A118811). The second is the curve with polar equation (6) which has the corresponding parametric equations (7)
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submitted by abhixx1 (20 m) on 26 Jul 2007 15:51:14 IST (1 comments 157 views)
Intro to Quantum Mechanics This page is intended to give an ordinary person a brief overview of the importance and wonder of quantum mechanics. Unfortunately, most people believe you need the mind of Einstein in order to understand QM so they give up on it entirely. (Interesting side note: Einstein didn't believe QM was a correct theory!) Even some chemists fall into that category-- to represent physical chemistry our departmental T-shirts have a picture of the below atom, which is almost a century out of date. <Sigh> If the above picture is your idea of an atom, with electrons looping around the nucleus
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submitted by nivedh_89 (4548 m) on 26 Jul 2007 15:24:51 IST (0 comments 97 views)
i heard from some of my friends that the pattern of jee has changed once again. and the new pattern is fully subjective . please reply at : ishan.maheshwari@gmail.com is it true ? --------------------------- all viewers must reply
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submitted by ishan.maheshwari (161 m) on 26 Jul 2007 12:02:33 IST (3 comments 231 views)
cool tricks to learn your course. Students, wouldn't you like to learn cool tricks to make it easier to learn and remember new information? Well, here's a challenge to use as many of the 13 memory strategies as you can. You will be amazed at the results! click on this link: http://www.ncwiseowl.org/kscope/Hovercraft/MemoryBooster/index.htm
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submitted by mukeshpal.pal (29 m) on 26 Jul 2007 12:26:26 IST (0 comments 161 views)
Coordination Chemistry Discussion Questions How did the study of coordination compounds started? How the number of isomers be used to determine the structure of a coordination compound? Coordination Chemistry Coordination chemistry is the study of compounds formed between metal ions and other neutral or negatively charged molecules such as [Co(NH2CH2CH2NH2)2ClNH3]2+ Cl22-. In this formulation, Co(NH2CH2CH2NH2)2ClNH3]2+ is known as a metal complex, which is a charged species consisting of metal ion bonded to one or more groups of molecules. The bonded molecules are called ligand. The little picture shown here depicts a structure of a 6-coordinated complex. A
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submitted by nivedh_89 (4548 m) on 25 Jul 2007 23:05:00 IST (0 comments 175 views)
Power of x. c = 0 x = 1 xn = n x(n-1) Proof Exponential / Logarithmic ex = ex Proof bx = bx ln(b) Proof ln(x) = 1/x Proof Trigonometric sin x = cos x Proof csc x = -csc x cot x Proof cos x = - sin x Proof sec x = sec x tan x Proof tan x = sec2 x Proof cot x = - csc2 x Proof Inverse Trigonometric arcsin x = 1 (1 - x2) arccsc x = -1 |x| (x2 - 1) arccos x = -1 (1 - x2) arcsec x = 1 |x| (x2 - 1)
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submitted by mukeshpal.pal (29 m) on 25 Jul 2007 12:37:06 IST (2 comments 175 views)
Powers. Powers of complex numbers are just special cases of products when the power is a positive whole number. We have already studied the powers of the imaginary unit i and found they cycle in a period of length 4. i1 = i, i2 = ?1, i3 = ?i,, i4 = 1, i5 = i, i6 = ?1, i7 = ?i,, i8 = 1, i9 = i, i10 = ?1, i11 = ?i,, i12 = 1 and so forth. The reasons were that (1) the absolute value |i| of i was one, so all its powers also have absolute value 1 and, therefore, lie on the unit circle, and (2) the argument arg(i) of i was 90°, so its nth power
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submitted by nivedh_89 (4548 m) on 25 Jul 2007 12:34:15 IST (2 comments 167 views)
This is related 2 our academic life and hence i have termed it ACADEMIC........God's Coffee A group of alumni, highly established in their careers, got together to visit their old university professor. Conversation soon turned into complaints about stress in work and life. Offering his guests coffee, the professor went to the kitchen and returned with a large pot of coffee and an assortment of cups - porcelain, plastic, glass, crystal, some plain looking, some expensive, some exquisite - telling them to help themselves to the coffee. When all the students had a cup of coffee in hand, the professor said: "If you noticed, all the nice looking expe
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submitted by nivedh_89 (4548 m) on 22 Jul 2007 21:11:22 IST (5 comments 180 views)
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