Formation Definition and 508 Threads

Hey, I've looked for a little bit just online and in the forums and still have not gotten a definite answer. My question: why does bond formation release energy? There is a reason I am posting this is the Quantum Physics section. I am very certain that the energy released into the environment is...

In Acid Rain caused by car emissions, how does NO2 and OH from water chemically bond to form HNO3 (Nitric Acid)? From the subatomic and a skeletal formula perspectives, please. Does one covalent bond overpower another? How does the formula rearrange itself step by step?

When we see an arc between a Jacobs ladder is this because a charge density builds up between the rods and then the E field between the rods is strong enough to rip electrons off the molecules in the air and the start to conduct.

How the depletion region act as capacitor? My view is that there are no charges because if formed of recombination of charges. so, there is no charge... So, how can it act like a capacitor? How the electric field is created in depletion region? It's confusing me a lot ...

Homework Statement Create cis-1,2-epoxy-1-phenylhexane from (E)-1-phenyl-1-hexene Homework Equations The Attempt at a Solution My teacher asked for two ways to create this and I think I've got the first. The first way was by treating (E)-1-phenyl-1-hexene with H2 and poisoned...

Hello everybody, I'm not sure if this post is more appropriate here or in the physics section (it's about biophysics topics): if it's off-topic here, please excuse me and move it. I was wondering if it's possible to calculate the enthalpy of formation of a gas molecule, in this example...

For my advanced physics lab course this semester, I recently conducted an experiment using a hyper-pure germanium detector to measure the energy of gamma rays released upon the formation of deuterium (DF). Essentially, I used a neutron source to bombard a hydrogen rich target (used both...

I have been having trouble with this for a long time 1st - How and Why is a image formed ? 2nd - If all objects reflect light why is the image not seen on all the objects Even walls reflect light but there is no image formation when light rays from an object reflect off an object and...

The understanding of the origins of our planet (as well as the other planets in the Universe) has always remained a question to astronomers. Inherently, the application of Newton’s known concepts of gravity has granted us the ability to make educated assumptions concerning planetary formation...

Hi all, I recently encountered this scenario. I placed a (1 litre) glass bottle with water (about half filled) that is corked up near my stove. My wife was cooking and the cork suddenly popped. We discussed this over dinner and I said that it was due the air in the bottle that has...

Hi guys So I went on a field trip with my class and this is one of the things we saw: http://74.52.147.194/~devilthe/uploads/1320293567.jpg Can anyone tell me what that is from? I think maybe it's from a glacier or something of that sort that caused it...but I really have no idea and...

A concave lens always forms a virtual image (for a real object), will it always form a real image for a virtual object? (that is, when rays converge on it) If yes, why? If no, why?

When a massive star dies, you either get a neutron star, or a black hole. From my lecture, neutron star are extremely hot object, with temperature around 10E11 to 10E12 kelvin. I'd assume black hole created from a similar process with just more mass, wouldn't have temperature any lower...

Homework Statement Take for example the problem given below: C + O2 → CO2 ΔH°f = -393.5 kJ/mol 2CO + O2 → 2CO2 ΔH°rxn = -566.0 kJ/mol To determine the ΔH°f of CO from the reaction of C graphite and O2 given those equations, one would solve it as: -393.5 kJ/mol + 1/2(566.0)=...

I would like your expert opinion regarding my hypothesis on the Mechanism for formation of Carbides in Upper and lower Bainite. My Hypothesis is as follow: Upper Banite: • The carbide particles of upper bainite tend to be elongated and form between ferrite laths, areas to be which carbon has...

Hi, what is Liquid Sprays how it is formed Do u have any PDFs or textbooks related to this

It is very common to see in the literature negative formation energies reported for point defects in solids using different simulation techniques ranging from Density Function Theory to Molecular Dynamics. The authors rarely comment on what does that mean physically. I will mention here two...

Is there any reason to expect both the star formation history and the angular diameter distance to peak at around the same value (redshift ~ 1.6)?

Hi Homework Statement I shall calculate the enthalpy of formation of gaseous hydrogen chlorid at 298,15 K with the usage of thw following data: \Delta [NH_{3}+HCL ->NH_{4}] :-50,4 kJmol^{-1} \Delta H_{form} NH_{3}:-46,2kJmol^{-1} NHCL_{4}:-315kJmol^{-1} and...

I know that the only dark matter models consistant with the cosmic microwave background radiation require bottom-up structure formation, but all of the relevant press releases I've read are about finding surprisingly large/mature structures in the early universe. Do the same...

So I've gotten into the Method of Frobenius and all; Solved a few questions, however the most inconvenient part would be the formulation of the general equations for the final answer. Granted, the lecturer told us to not spend so much time on that segment due to its minimal weightage, but I...

Is there any way to economically produce positrons using particle accelerators or any other method?

I am not a scientist, just an observer and an enthusiast. I have read that the moon was formed by a huge collision between the Earth and another large body. I was wondering if this had any affect on the Earths position in the solar system. Could it have moved the planet at all? With the extra...

I was watching How the Universe Works, and they mentioned that planets were formed by dust particles that came together to form rocks, and that those rocks collided with one another and became larger and larger eventually forming planets. My question is why did the asteroids in the asteroid belt...

Homework Statement Homework Equations Thin lens equation: 1/f = 1/s + 1/s' The Attempt at a Solution I tried to define image and object distances for both instances and equate them. Didn't work out :( Any help is welcome!

Are there any usable simulation in the literature on the formation of a solar system? It is possible for example that a solar system has 100 big planets?

I just finished up my first class of chemistry, and have a question on something that I just can't figure out. The delta H of formation for diatomic molecules is 0. I just don't understand why this is. If there is a reaction, and O2 is one of the products, why is there no heat released when...

Hello, I am attempting to calculate the amount of condensation formation on the underside of a roof (steel sheet). moist air is on the underside of the roof, ambient air on the upper side I know the following properties; RH of moist air Temperature of moist air, T1 Temperature of...

Hi everyone, This is my first thread so I'll try to be as clear as possible and try to follow the rules. My job is to synthesize silver nanoparticles, characterize them (TEM, DLS, EDAX, Z-POT), and then pass then on to the toxicologists. This is my thesis work to graduate. A new thing I have...

I'm thinking about the thermodynamics of electron capture: p + e --- n + v(e) + energy (That is, proton absorbs electron to give neutron, electron neutrino and energetic photons.) This is thermodynamically disfavored given the substantial energy barrier to fusion to a neutron...

Homework Statement I am investigating the penetration depth of eddy currents within a copper slab. A solenoid is being used to induce the eddy currents within the copper. As a result of the experimental design, I need to calculate the power loss due to the eddy currents and I can't find any...

Is the combination of an positive sodium with a negative chlorine neutral ? If so, what attracts and holds together other sodiums and chlorines to make a grain of salt ?

Dear Internet- As part of an introductory Astronomy course, it is time to compile a mock research proposal, specifically to give us an idea of what real scientists do. The purpose of it is to focus on a particular not-yet-understood phenomenon of astronomy, and describe the process we would...

I'm hoping someone can explain how the formation of a chemical bond releases heat. What I imagine is that, when two atoms that are about to bond come near each other, they (or at least some of their electrons) accelerate forward under the influence of an electrostatic force. When these...

Earlier today I took a break from following the thread here on the Fukushima Nuc Plant problems (very interesting, by the way) and watched some TV, specifically a show I recorded on the formation of Stars. It reminded me of something that has been bothering me for some time - Gravity and how it...

If gas has to be cooled below, say, 100 K, in order for stars to form, what is the highest redshift for star formation? What would be the necessary equations to solve this problem??

In the first part of Brian Cox's documentary series 'Wonders of the Universe', he explains how the entropy of the universe always increases, and that we are therefore headed for a state of total 'disorder' where all is left of the universe is photons and dying black holes. But wasn't this...

Homework Statement r=kt^1/2, where r-rind thickness(L), k= weathering constant (L/T^-3), t= time (T) if the rind thinckness is 0.25cm and weathing constant is 0.14(cm/kyr^-3) how long has the material been exposed to weathering? if the weathering constant has an error of +/- 15% what are...

Hi, I was just wondering if anyone could shed some light on how this ice spike formed? All I did was fill a 4" tall, 4" diameter plastic container with water and put it in a normal refridgerator freezer. I came back the next morning and found what you see in the photos. I likely used...

Can someone explain to me in detail formation of depletion zone and doping. I thought i understood this but it confused me when it came to this depletion zone. If u dope silicone with a substance with 3 valence electrons this forms a hole right? How does atom then behave? Does it polarize...

Homework Statement Pure oxygen was first obtained in the laboratory by the French scientist Antoine Lavoisier in the 18th century by decomposing red mercury(II) oxide, HgO, to give silver mercury liquid and gaseous oxygen: 2HgO(s) \Leftrightarrow 2Hg(l) + O2 (a) From values of \Delta f...

Most people on this forum know the basic theory of black hole formation. When a massive star runs out of fuel there is no longer enough heat pressure pushing out against the gravity pulling in and the star collapses. The density of the core and resulting remnant become so large that nothing, not...

Hello According to general theory is there any explanation of tidal wave in sea due to gravitation of moon. How moon warp space time in such a way so that tidal waves are generated in sea?

First time poster and non-cosmologist. Why can't we use telescopy (across the EM spectrum) to view the formation and development of our planet? Let me explain by laying out some assumptions (correct them if they are inaccurate). - When we use telescopes (again, I mean x-ray, radio, visual...

Homework Statement The cation [CH2=CH-CH2]+ has a delocalized pi network that can be described using Huckel Molecular Orbital Method. Calculate the pi bonding formation energy 2. The attempt at a solution Using matrix, energy = alpha, alpha + root2 beta , alpha-root2 beta The pi...

There are many ideas on how the universe came into being. Please put ideas on how into the replies/comments, as I would love to hear, and debate them. Thanks!

Hi guys I've been trying to make a program that simulates image formation in the eye so I simulated a spherical lens behavior in 3d coordinates and I'm facing a strange results! is it normal that the refracted rays don't intersect all at the same point I began to think it's true because of...

First of all, I know that that very large stars tend to form black holes, and smaller stars, but still massive in comparison to our sun, tend to form neutron stars. My question is, if matter is lost when a star collapses into a black hole, but can still form one, why is it that it is a star...

Homework Statement When using the equation, Q=ms∆T, is the heat always positive? Homework Equations heat of formation = q/mol (but of course the moles used in this lab is a positive number)The Attempt at a Solution I'm working on the energy of magnesium lab where magnesium ribbon contacts and...

How many routes are there to the formation of a black hole? A high-mass star can evolve off the main sequence, then end up going supernova and leaving behind a black-hole remnant. In this thread https://www.physicsforums.com/showthread.php?p=3062281 , Radrook and Jim Graber pointed out that...