Formation Definition and 509 Threads

Hello. First post here so hi all. My question(s) is regarding the formation of solar masses by accretion of gases and dust. From what I understand, stars are formed by large clouds of gasses and dust particles pulling together and with enough gravity, (magnetic fields), and time. A fusion...

If -Nh2 terminal become Nh3+, is this bond formation release energy in terms of entalpy decreasing way?

"There are various theories about how the solar system formed, but scientists haven't been able to agree on a single model that explains all the quirks of our corner of space as it exists today. Now, scientists at the University of Chicago have...

I have to 'question' the logic asked in the 'title question' asked in this artical: https://newatlas.com/most-distant-supermassive-black-hole/52508/?utm_source=Gizmag+Subscribers&utm_campaign=2151ebbb0d-UA-2235360-4&utm_medium=email&utm_term=0_65b67362bd-2151ebbb0d-91583997 It seems to me that...

Homework Statement Find the Thévenin resistance for each of the circuits shown by zeroing the sources. Homework EquationsThe Attempt at a Solution I replaced the current source with an open circuit and I'm left with a wye formation but I don't know how to calculate the equivalent resistance

Hello When mixing a strong acid and water, the temperature increases. There is production of water molecules from H + and OH- ions. If you plunge a glass of pure water into an intense electric field, the ions present in the pure water will migrate. The pH equilibrium will no longer be...

I am curious as to what is the Standard Enthalpy Of Formation is of Tetraoxygen in kJ/mol. I am assuming reference to the molar weight of the Tetraoxygen molecule. I seem to only find papers on the subject which are abstruse with detail but no clear answer to my inquiry. I have little formal...

I am curious as to what the Standard Enthalpy of formation of Graphene is. I've noticed several highly technical papers on this subject but I got lost in the abstruse math and terminology. I am interested in the Standard Enthapies o both single layer and multi-layer graphene. I will be happy to...

Homework Statement I am not sure I understand how did they solve question (b). Here's the solution to question (b): Homework EquationsThe Attempt at a Solution For the first approximation I plugged everything to the identity in (a) and indeed got the approximation as it's written in the...

So I was wondering why do nucleons need to remove mass to form a nucleus. Is it because it lowers the energy of the nucleus making it more stable or something completely different. I understand that it is the energy input to break the nucleus into its components, however, why do nuclear reaction...

"Today's astronomers detect objects so far away that their light has taken perhaps 10 billion years to reach us." -NatGeo May 1974 page 595 If there was a planet and the light that has been reflected from Earth was reaching there 4.5 billion year later (that means it would be 42.75 trilliard...

Hello! If energy bends spacetime, then an object moving at high velocity will bend spacetime a lot around it due to its really big kinetic energy. It follows, that an object can become a black hole at extremely high enough velocities. But, since velocity is relative, we can find an observer for...

I've been working on a crude N-body simulator which allows N bodies of equal masses to interact gravitationally in 2 dimensions. My goal is to model the formation of Solar System. Each body is modeled as a circle with a radius as a function of its mass, in such a way that all bodies have the...

Cheers community, I have been studying the Struvite formation from respective ions. Being the general formula for Struvite MgNH4PO4.6H2O I intuitively tought the reaction would be Mg2+ + NH4+ + PO43- + 6H2O↔ MgNH4PO4.6H2O. However from literature and from practice, not only the optimal pH seems...

Hello all, To my knowledge, there are still a lot of questions regarding the specifics of black hole formation. My question is in regards to formation time. I've read that the actual formation takes "less than a second" according to the equations. Does anyone know where time shows up in the...

So stoney and metalic asteroids formed from dust and gas condensed from plasma. You would think they would be fluffy, dust piles, unless they had been part of a body large enough for its own gravity to melt it--large enough to form a sphere? Yet we're told that Sol's asteroid belt was never part...

My textbook says that formation of petrified trees is a result of a degradation and a sedimentation action of theunderground water, and then it goes on explaining that the underground water replaces the plant material in the tree with silica and other inorganic materials, which I think is a...

Does anyone know how long the lunar month was when the moon was formed? I can't get the equation to work. I'm looking for speed of the moon when it was created at about 1/10th the current distance from the earth. Thanks.

Sorry if this is a stupid question, I don't fully understand entropy. Snow flakes are highly structured, they form from water vapor which has very little structure. I must be misunderstanding entropy, my interpretation of it is that isolated system must evolve into more chaotic less structured...

Assume a spherical region of breathable air just under the density needed to form a low density supermassive black hole. Two people float 20 feet apart from each other exchanging small talk. As gravity does its work, the spherical region holding the person closer to the center reaches the...

I have a question, it has to do with the formation of stars and how it is triggered. I was reading that any given stellar body with enough mass would collapse into a star, does this mean that any type of matter you put in space regardless of what it is, given the correct conditions will turn...

Arxiv and google searches turn up hundreds of sources on Galaxy formation. I'm specifically looking for good material on how Dark Matter distorts the motions of galaxies from what we'd expect. Currently I've been using a combination of Binney and Tremaine's Galactic Dynamics and whatever...

Recently watching a documentary about stars (how the universe works), I was wondering about two things. The first one is: how is it possible to have stars with such a wide range of sizes? As far as I understand, stars are created in swirling gas clouds, nebulae. When the accumulation of gas...

Homework Statement Find the order of the differential equation of y=C1sin2x+C2cos2x+C3. Homework Equations - The Attempt at a Solution [/B] I read in my book that the order of the differential equation is equal to the number of arbitrary constants but the answer given is 2. Btw I have...

So when they said that to produce water vapor at standard state it releases -241 KJ/mol and liquid water -284 KJ/mol You can't create water vapor at standard temperature but I assume they used Hess' law Anyway, my question is when you change from water to vapor you need 44KJ/mol So that would...

I get terribly confused to consider which rays for determining image formation via concave and convex lens? Many times examples take 3 rays into consideration - 1) A ray passing through Focus 2) A ray passing Optical Center (center of curvature) and 3)A ray parallel to principal focus. But the...

I was wondering if excess hydrochloric acid was produced during the reaction to make Nylon 6,6 (interfacial polymerization)?

Situation, a empty universe where there are only concentric spherical shells of mass dm spaced apart by distance dx and contracts under gravity to form a sphere. Assume that there is a point mass in the middle of all the shells. I don't think it would work without it. case1 is an inelastic...

I was reading about the pressure which is created when fermions are close of each other like in an electron gas, and I started thinking about what causes a black hole to form. Firstly, what happens when two fermions are forced to occupy the same place (and state)? By the exclusion principle I...

I read that time dilation near a black hole's event horizon causes the infalling matter to "freeze" just above the event horizon and never cross it (in a distant observer's frame of reference). Doesn't the same phenomenon prevent the event horizon and singularity from being formed in the first...

Homework Statement I do not understand how in tetra amin copper(2) ion there happens the sp2d hybridization.I understand that the dsp2 hybridization seems unreasonable .But if the the electron of copper ion really needs to be in the last D orbital ,then why there can't happen sp3...

I observed that if you pour soda into a glass cup and leave the straw inside, bubbles seem to form on the plastic cup at a much much quicker rate. Why is this? Why do bubbles form on the straw at all? Not sure if this should be in general physics or chemistry

I always wondered why they say water and photons created the first microbes which later evolved and produced oxygen which filled our oceans and atmosphere. So how could have water existed without oxygen? I tried to look up and came up with different explanations, but it doesn't make sense.

Hi guys, This is basically a quick question to hopefully find some pointers on a topic I've been browsing the internet on to not much success. Basically the topic I'm trying to find more information on is the angular momentum problem with the "nebular hypothesis" of the formation of our solar...

The stars formation decreases the entropy but the radiations given out increases the overall entropy i am said ...but once the fusion processes are over the star no longer gives out radiations...and still the volume in which the matter particles of the star can be becomes less as the star...

I have been reading about and contemplating the early stages of star formation lately. An interstellar cloud collapses under it's own gravity to form a star. There is much data about what could trigger it, and what happens when the gas heats up or starts fusing. However, i couldn't find...

Hello! I watched a video on the Youtube channel Kurzgesagt titled How far can we go? Limits of humanity The video attempts to explain why we may be limited to our local galaxy group even with science fiction technologies. During a part of the video (starting at 2:26), they try to explain how...

Hi. I'm trying to proof the image formation property of a concave spherical mirror. I know you can do this easily with a particular choice of rays (namely one that hits the vertex and one that passes through the center of the sphere) but I would like to show that a generic ray yields the same...

How a potential well is formed? Can mass of a wave creates a potential well?

Homework Statement Ok, these questions are very simple but they are really bugging me and I would greatly appreciate an explanation. Question 1 is "which of the following elements must have been made in stars". The options are hydrogen, helium, carbon, oxygen and iron. Question 2 is "which of...

When determining the formation energy associated with a point vacancy in say a monoatomic crystal - when the total energies of both perfect and defected crystals are known - how exactly is the chemical potential determined? Formation Energy should be given by expression...

For water in a tube wouldn't meniscus formation increase the free surface area of water

Has anyone analyzed the process of Neutron formation and decay from the perspective of "information conservation"? Does anyone have any thoughts on what the results of such an analysis would be? What is the status of the observed evidence of reality in respect of whether one should conclude...

Can someone point me to the seminal (or any other) paper explicitly showing and proving the formation of singularities in black holes? I'd like to learn about the exact physical processes which occur during the collapse of a star into a black hole and how the progress of those physical...

So a programme that I watched on tv was talking about neutron stars and they said that the neutron stars neutrons were formed by protons and electrons combining to make neutrons. I was just wondering, how does this work, in the field of the quarks in the proton and how they are effected by an...

Hello, This problem is about cooper pair formation and what happens with the calculations if there is an attractive potential between electrons but it is not in the presence of a filled fermi surface. 1. Homework Statement Two electrons just above the filled Fermi Surface of a material can...

Is there any way to design a lens or system of lenses where I see the same part of the image, irrespective of direction or angle of view. The light rays can be assumed to be collimated as viewing will be from a distance. Actually- I am looking at focusing on a point or specific area of the...

What will happen if look at(or in the direction of) a distant object through a convex lens?

Homework Statement What do we mean by ion-ion repulsion during micelle formation in soaps? Homework Equations None The Attempt at a Solution I think It is about the positive and Negative charges of water getting repelled by the positive and negative charges of hydrophilic end of soap...

The usual way to explain the formation of a Schottky barrier between a metal and semiconductor is the following: Suppose a metal and a semiconductor with different work functions are put into contact. To compensate for the work function difference ΔW of the two materials a charge layer will...