Atoms Definition and 853 Threads

Where i live in the UK all the A-level students have just had their results. It has been said on the news that a new A* level will be added to the A levels to differentiate between the bright and the very bright and that an example of an A* question would be: 8 million uranium atoms in...

Victor Stenger has proposed a model of the universe consisting only of atoms, void and time reversability. I like this idea, partly because it's almost simple enough for me to understand. But I have a problem with it. He suggests that the universe can be explained as atoms and void, as per...

How do you calculate the distances between atoms of a given gas molecule? The reason I am asking this is so I can find the moment of inertia of certain molecules so i can determine degrees of freedom for a gas at a certain temperature. Is there an easier way to determine them?

Hi guys, I've got a little conceptual question here. I became a little confused after my exam. Firstly, I understand that in the photoelectric effect, the electrons either accept all or none of the energy from the particular incident photon and the photon must have a minimum frequency...

Hello In DNA, thymine and adenine molecules are attracted to each other. The solid lines show bonds between atoms in the same molecule and the dotted line shows bonds between atoms in different molecules. Atoms in the same molecule are separated by 1e-10 m. If the net charge on the H and N...

hiya 1) 2) 3) thank you

How many atoms could fit inside a human cell? "A person's body is actually made up of trillions of cells (source: Science Concepts - Cells by Silverstein)", but how many atoms could fit inside a human cell? 125 million atoms could fit inside the period at the end of this sentence. But how...

Hi Everyone, I was reading this post here (https://www.physicsforums.com/showthread.php?t=206&page=3&highlight=oscillator) where the poster was asking what keeps electrons from falling into the nucleus of the atom due to the unlike charges of the electron and neutron. This raised another...

hi, i have a qns as follows, any help will be great apperciated. A helium nucleus of velocity " v" enters a magnetic field and moves in a circular path of radius R. A proton having the same initial velocity that enters this magnetic field will then move in a circular path of : a. R/4 b...

Is it possible to imitate the repulsion of atoms of gas on macro-scale? (I mean: atoms of gases repell all other atoms around it using some force. Among them there is nothing (vacuum) - isn't it. Well... - imagine if you could make a macro-object that could repell all matter (atoms) (a sort...

"Teleportation" of single atoms I've recently heard a lecture that dealt with semiconductors and using them to create pairs of entangled photons on-demand. As a side note the Professor noted that this might open a possibility of "teleportation" in the future, and that it's actually been done...

If we have a molcule of 2 atoms, and the potential energy between them is given as a funcion to the distance between them r: U(r)=-A/(r^2)+B/(r^10) Where A,B are constants, How can we calculate the FORCE and ENERGY required to completelty separate them? and how can we calculate the force...

could, theoretically, atoms ever run out, though it is very unlikely. Please Respond:cool:

Hello, Does anyone know why in pionic hydrogen the strong interaction should be attractive whilst in kaonic hydrogen it is repulsive. I have heard it is something to do with a sub-threshold resonance but nothing more. Thanks Sham

Who came up with the idea of an atom? It begs the question why do such people waste their time on this when they know they can never really find out what's going on? I bet instead of the four known forces there are litterally hundreds of millions of 'forces' each binding everything on such a...

I couldn't really simulate this in my brain, What will happen when atoms are compressed up to an infinite level ( extreamly great presure ) Will the atoms split up? if so what will the product be?

Hello, Does anyone know how to prove that the size of atoms is nearly 10^-8cm?:rolleyes: Thank you

This appears to be a rather useful overview of the history of high energy/particle physics. I glanced through it quickly, but can someone who is more familiar with this field of study verify that there's nothing obviously erroneous with this? If there isn't, this could be a very good intro to...

say for example, a question states that you have 18 g of H20 which is obviously one mole. now if they asked how many molecules of water you had, you would just multiply the one mole by avagadros number (6.022 * 10^23) to get that answer. if they asked how many atoms of water, would it be...

For two hydrogen atoms separated by 3 Angstroms, what is the main force (cause) for the two atoms to move closer toward each other? As the atoms get closer, does a different force (cause) dominant the original force that started the attraction?

I have a question i am having trouble on. "A proton is traveling with a speed of (6.560+0.012)*10^5 m/s. With what maximum accurancy can its position be ascertained?" Any help will be appreciated.

Hi guys, I have this question I can do the first part but not the second, any help would be appreciated. Thanks in advance! :cool: o:) --------------------------------------------------------------------------- http://img381.imageshack.us/img381/6778/ocau9rj.th.jpg Question 1 A photon...

Just wondering, why are some atoms radioactive and others not?

Hello, there is one thing about atomic states I don't understand. I try to look at what states are possible for a np^2 configuration (that is, all lower shells are filled and don't contribute to the case). For example my textbook says that the ~^1 P state is not allowed because of the Pauli...

how do atoms transfer kenetic energy to each other?

A question concerning atoms in magnetic fields: Why does the LS-coupling break down in a strong magnetic field (Paschen-Back effect)? I have until now only gotten this stated as a fact, but if anyone could give a few arguments it would be appreciated. Why aren't the individual components of...

Atoms have no random details ? If you look at anything macroscopic there is a lot of random details. Like the leaves on a road, or the cracks in a wall etc. Why don't atoms have any random details? They are perfectly round with "points" (electrons) that circulate them. OK, they are not...

I was thinking , if we take into account oly the internal motion of atoms , all collisions will turn out to be elastic. Wont they be?

All right, so what I don't understand about the big bang theory is that when it describes the creation of atoms, does it mean that the particles were already in existence and the explosin only made the particles come together? or were the particles actually created by the big bang? If the...

Me mate says that that you can make Steal from mixing Carbon atom and Oxygen (Transmution) :eek: Basicly stuffing arround with nuclues. As far as I can remember you can't touch the nuclues as the EM forces are too strong. How wrong is he? We made a bet of $20 :smile:

The question is the title.

this is homework problem I'm having some trouble with... i haven't had chemistry yet so I'm not sure how i could convert atoms into kg, and the textbook i have doesn't do any examples of problems like this one... i don't even know where to begin. Deuterium (A=2, Z=1) is an attractive fuel for...

In a mixture of Ne and He at equilibrium, all of the He atoms move faster than all of the Ne atoms. Why is this false? Shouldn't it be true, since Ne atom is heavier than He atom. Thanks for any help

I wish to know whether gravity has any effect on atoms? And if so to what extent ?

I was thinking if you entangled both the electron and positron in a states that both of their orbitals don't interact. Or just entangle the electron with a helium higher orbital electron. Or you entangled a muon with a helium proton(is that even possible?). Is there any way to keep a...

If one could observe the individual atoms making up a piece of matter and note that during a process of change their motion somehow became more orderly, than one may assume which of the following in regard to the system? a. increase in entropy b. decrease in entropy c. gains in thermal energy...

I'm doing an assignment for grade 8 science in which I have to prove whether or not atoms are fact or fiction. I was just wondering if anyone would be able to give me a few tips to help me out with this. :smile:

Hi, i understand that fission breaks apart radioactive atoms into smaller 'slightly more stable' atoms.. and that this process continues until the atoms break down into stable atoms.. i have been wondering if a radioactive atom/isotope once broken down into a stable atom/isotope would...

Does anybody have any thoughts on why atoms that are warm need to radiate heat in order to stop vibrating or bond back together? The obvious example is the thermos. That is a thermos has the hot liquid contained in a glass container with a mirrored surface towards the inside and then a...

I am to arrange the following atoms or ions in order of increasing radius...then give an explanation for the position of S2- in relation to the atoms or ions that come before or after it. Here is what i have so far...in order of increasing radius. K+ K O S2- Cl Now I am not sure...

I am looking for ways to illustrate the chemical makeup of minerals. I belong to a mineral club and I am scheduled to give a presentation to the children about the polymorph mineral group of Kyanite, Andalusite, and Sillimanite. I would like to have images of the atoms that make up these...

When a photon hits an atom it gets absorbed and an electron moves one or more shells up depending on the energy of the photon. When a bigger, many-electron atom gets hit by a photon, can the electrons in the lower shells get excited? I mean when they move up they have to remove the electrons in...

Since my brain is made of atoms I question as to whether atoms are conscious, at least in the brain but possibly even in inanimate objects, possibly varying levels of self awareness.

I'm trying hard to find a decent explanation for someone that an expanding universe doesn't mean that galaxies get stretched out and made bigger; that the planets won't get further away from the sun; that we don't grow bigger etc. I've googled and searched about but a decent explanation of...

Hey, I've just been studying the Bohr model at school and have had a nagging thought in my head. If we have electrons wizzing around an atom. They will slowly collapse into the nucleus (due to gravity & magnetic forces of attraction) and well I guess something will happen that won't...

help pls! since electrons cr8 a magnetic field due to their spin, shouldn't atoms be magnetic? o0

A plasma consists of both ions and uncharged particles of gases. Is it possible for the uncharged particles to fuse or only atoms whose protons have been stripped off can fuse?

How do we determine the magnitude of the nuclear force acting on the nucleus of an atom?

http://xxx.sf.nchc.gov.tw/pdf/hep-ex/0503034 This paper is a review of anti hydrogen production, and how it could be used to test gravity theories.

Three (3) Questions: 1. Keeping in mind the light emitted by Synchrotrons, then taking the electron as a point charge, and assuming that it orbits the proton in accord with a proper 1s type wave function, does that electron continuously emit (and/or absorb) radiation other than virtual pairs...