Formation Definition and 480 Threads

I don't believe the cloud formation by particles from space idea because why would they be doing this now (we'd have to be unlucky given geological timescales) and why isn't there evidence of this in the past.

In my textbook, it had 2Cu2+(aq) + 4I-(aq) -> CuI(s) + I2(aq) How does that work? First of all it's not balanced. It should be 2CuI(s). But how does CuI(s) form. It should be CuI+. The book did say excess 4I- was usd to remove Ag+ since it was talking about back titrations. But the...

Since in our proper frame of reference the fall of material into a black hole would appear to take for an eternity, would it not follow then that all black holes would appear as these instead? Would in fact all black holes appear this way? What if you have a small black hole and then have...

When i read "Alternative" i immediately thought "crackpots!", but then I read on and found out they're on to interesting stuff. http://www.physorg.com/news85310822.html

Hi Basically, I am doing an A level project, in which I am investigating impact craters. I am modeling this by dropping ball bearings into sand, and measuring the depth and width of the resulting crater. However, my results are quite unclear, and I would really appreciate some guidance...

I read in the book of world records that there are massive diamonds inside of some white dwarves. If this is compleatly true then how long after it's formation could a white dwarf start producing this massive diamond in it's core?

under what circumstances phenol forms phenolate with max yield

Hi, I have a question involving enthalphy of formation. I tried doing this problem but I couldn't seem to get the right answer. I was wondering if anyone here may please help me out. Thanks. Question: How much heat is evolved when 13.39 moles of CO(g) is burned in excess oxygen. 2CO(g) +...

I have no idea whether or not this is a ridiculous question, so I am just going to ask it. My question is based on the concept that energy must be added to ions to get them to form compounds (such as the formation of hydrogen iodide). Typically (or so my chemistry textbook says), the addition...

Here is my question in the formation of Schottky Diode: "Why does conduction band is lower than the original value in the semiconductor side?" And I think it is lower because the postitve charged donor ions provide a attractive force ,which makes the electrons in semiconductor more easy to...

I've google and read, but could anyone tell me how to find out the standard enthalpy of formation for any compound? :confused: thnx

[FONT="Comic Sans MS"][SIZE="2"] OOPS I didn't see this forum I posted this earlier in the "Other Sciences > Chem." section...Sorry about that! My original post is below... Hey guys this is my 1st post here...Need help with a question that's been troubling me for a long time... A student...

[FONT="Comic Sans MS"][SIZE="2"]Hey guys this is my 1st post here...Need help with a question that's been troubling me for a long time... A student determined experimentally that 2.06 kJ of heat energy were released when 0.365 g of copper reacted with excess chloride. From these data, the...

Hi, I am working on a project that involves molecules of water vapor, hydrocarbon and O2 being broken down by a laser beam (193nm) and ozone being formed as a result of that; and was wondering if anybody could explain the phenemenon to me (even briefly), or point me out to the right...

I need some heats of formation for a chemistry teacher I'm helping. If anyone could help me out that would be great. These are the ones I need: SO3-2 S2O8-2 OCl-1 Thanks again.

How do these come about, also what are the leading theories behind the formation of these objects?

Hello, I am new to this forum and guess what :P my first post is going to be a question, well, a few. Why do crystals form at low temperatures? What physics are involved with this? are there any articles on this subject (ive tried looking, but havnt found anything so far)? thanks!

What evidence do we have that stars are forming right now? Molecular clouds? why do we know that molecular clouds are where stars form? any other lines of evidence? i know this is a big topic so a few reasons or a good link would be a good start for me to understand this big topic thanks

When a cation and anion combine to form an ionic compound, the cation is usually written before the anion. I.e. NaCl But with some ionic compounds like sodium acetate, it is written with the anion acetate written first. i.e. CH3COONa Why like this?

I had a thought the other night when I heard that there is a super massive black hole at the center of every galaxy. My thought was is it possible that the big bang did not happen once trillions of years ago? Is it possible that every galaxy was created by its individual big bang from the...

In a recent theological discussion, I came to realize that there is a point in question regarding planet formation in the current model of the origins of the Solar System. The question itself is not theological, but has some theological ramifications. It goes like this: Planets are believed...

:confused: 1.) Is it possible for the number of neutrons and the number of protons to be equal? 2.) Is it possible for the mass number(nucleon number) and atomic number(proton number) of an atom to be equal? 3.) Is there any energy invovled in the formation of mixture? 4.) does...

In the case of nanoparticles is there any diffrence on the results (particle size and the other properties that are dependent on particle size) of two similer samples, one of which is annealed after pellet formation and the second sample is annealed in the powdered shape and then pellet is...

I have a chemical equation and the molar enthalpies of formation for its products, along with the total change in enthalpy for the reaction. With this I can easily find the total enthalpy of the reactants. In this case, there are two reactants and I need the molar enthalpy of formation of one of...

Sir, Ice starts forming in a lake at 0 degree Celsius, when the atmospheric temperature is -10 degree Celsius. If the time taken for 1 cm of ice to be formed is 7 hrs, what is the time taken for the thickness of ice change from 1 cm to 2cm? Can you please give a hint to solve this problem?

Could the process of star formation in a collapsing gas cloud transform the process of virialisation and ultimately promote the formation of a central black hole? Consider the following idealised and oversimplified scenario. Suppose a gas cloud massive enough to generate vast numbers of...

can u help me to explain the role of gravity in the equilibrium of stars in their production of enegry , and an explanation of the role of gravity in the formation of planets. thankssssssss

Has anyone ever formed water by manmade process? How is water formed and what conditions need to be met?

91. Write balanced equations to show the formation of each of the following compounds. Name the reactants in each case, and show clearly the removal of the water molecule. a) butyl propanoate b) propyl methanoate Answers: a) butyl propanoate- C[SIZE="1"]7H[SIZE="1"]14O[SIZE="1"]2 =...

Write balanced equations to show the formation of each of the following compounds. Name the reactants in each case, and show clearly the removal of the water molecule. a) butyl propanoate b) propyl methanoate Im not exactly sure how to answer this question... below are pics of the...

I've been reading articles on star formation and would like to know what the Pre-main-sequence actually stands for. Since more or less each stage of the formation of a star have names what type of star are inclusive in the PMS? How can you point out a PMS star from a main sequence star?

Write balanced equations to show the formation of each of the following compunds: a) butyl propanote b) propyl methanote I am doing a horribly constructed independent learning course, they offered absolutly no information on this topic, and then asked me to solve this question.. I really...

I am looking for good information about the formation of earthquakes. My textbook is not very good and Wikipedia did not satisfy me. I know that someome might have a good site or article about this topic. Thank you. I will continue to search, if i find one I will warn you. Thank you! :biggrin:

what is the product formed when Br2 is added to 1-methylcyclopentane?

How are metallic bonds formed? Does it have anything to do with the merging of d orbitals to obtain a half full shell configuration or is it something else? Thank you for your time. -Scott

Ok, on this one I have no idea where to start. I could do all the homework ones, but have no clue even where to start on this. To me it seems backwards, but who knows. Here is the question: Calculate the standard heat of formation of acetaldehyde, CH_{3}CHO , given the following information...

For the following molecules and ions, indicate the obitals involved in bond formation. 1) SO2 The central atom is S, and it has 1 double bond with a O and a single bond with the remaining O. There is also 1 lone electron pair. Therefore, a S-O bond is sp^2-p while a S=O bond is sp^2-sp^3...

can anyone tell me how planets form and how we know that life can only exist in an environment where there is liquid water. is it possible that we only know how to observe or measure lifeforms we have previously encountered?:confused:

http://arxiv.org/abs/astro-ph/0510697 Authors: Rychard J. Bouwens (UCSC), Garth D. Illingworth (UCSC) Comments: 5 pages, 2 figures. Conference proceedings for The Fabulous Destiny of Galaxies: Bridging Past and Present, Marseille, June 2005 HST ACS and NICMOS data are now of sufficient...

I'm reading up on star formation and from what I've understood so far, is that protogalactic clouds with density fluctuations cool and then fragment after which, they fragment again into subfragments. Now do the density in these individual subfragments increase the temperature enough to start...

This question involves the following statement in Schutz, A First Course in GR, but you don't need to have a copy to answer it. He says that in the formation of a black hole from a supernova explosion, we should expect gravity waves of amplitude M/R, where M is the mass and R is the distance...

hello. I'm studying philosophy, I'm going with a scholarship in France. I'm very interested in physics, particularly in quantum physics, and universe formation, laws,etc. I'm not directly interested to find books, or get an advice what to read. i want to discuss some issues with someone that...

When will the Last Galaxy be created?..are the Newest (detected) Galaxies part of an ongoing process, or is there is definate Closure to their Existence/Creation. And are there more or 'less' Galaxies being created at this present epoch?..or was there a definate period of 'MASS-CREATION' (I mean...

The CDM model predicts the existence of lots of dark halos without star formation. These are halos which did not attract enough baryons in order to set some kind of gravitational instability, which could lead to the further collapse of the baryons and to star formation (see, e.g...

http://arxiv.org/PS_cache/astro-ph/pdf/0506/0506156.pdf Title: Masers and the Massive Star Formation Process: New Insights Through Infrared Observations Authors: James M. De Buizer (1), James T. Radomski (1,2), Charles M. Telesco (2), Robert K. Pina (3) ((1) Gemini Observatory, (2)...

A hypothetical question: Say that Newton's constant G is increased a bit during the period between weak interaction decoupling and the time when photodisintegration becomes ineffective, and the helium is formed. (I.e. during the period when neutrons just decay). Would that give a larger or...

The formation of products is strongly favoured in the acid-base system: HX + B- <--- HB + X- ----> a) Identify the bases competing for protons. b) Which base is stronger? c) Which is the weaker acid, HX or HB? d) Does the K for this system have a large or small value...

AFAIK hydrogen was one of the first elements in our universe, i came to wonder, what conditions would prevent hydrogen from forming, and our universe consisting of only radiation?

The Following two questions are giving me the worst time. Maybe someone else can lead me in the right direction. Question 1: You unconsciously estimate the distance to an object from the angle it subtends in your field of view. This angle \theta in radians is related to the linear height of...

Note: This isn't an actual homework question, and I tried asking others (including teachers), but no one could answer it. Now, the heat of formation for sodium hydroxide is -425.6 kJ/mol (so it's exothermic). When you dissolve NaOH in water, the reaction is exothermic. But this is...