Atoms Definition and 853 Threads

Hi People all know that a neutral atom has no net charge. Well, does that mean that it neither creates an electric field nor is affected by any electric field? I wonder whether it's correct or not, because the distance between a test charge outside this atom is closer to its electrons...

Help with a debate on atoms at work? Hey all, For the last few hours we have been debating whether our bodies in reality are 99.999999999999% and so on empty space. I have studied physics at GCSE, A-level and University so I'm well aware that atomic nuclei are roughly 10^-15 meters and an...

I have a surface (paraffin) and a vapor of atoms (alkali). When atom get the wall, it is sticked for some time, exchange it energy and momentum with wall and then release. I want to know the atomic velocity distribution (both in directions orthogonal and parallel to the surface) after atom...

This thread is intended to ask the question about potential future sources of energy to experts, explain a few things and generate discussion about the future of energy and it's possible uses. Nuclear power is great. But it requires a bulky apparatus and very specific materials. Perhaps...

Question: A hydrogen atom has one electron. If we heat hydrogen gas up enough, we will completely separate each electron from each hydrogen atom (called "ionization"). What will the spectrum of ionized hydrogen look like ("ionized" means that the electron has already been taken away)? Here's...

Hello, does hydrogen atom with a single electron have p orbitals? when the single electron of the hydrogen atom is excited, can it go to the 2p orbital? are "p orbitals" consequence of electrons interacting with nucleus ( protons ) ? or are "p orbitals" consequence of electrons interacting...

Hello. I have a non-stoichiometric reaction that balances out to: C12H23.4 + 12.265(O2) ---> 11.7(H2O) + 6.415(CO2) + 5.585(C) The problem started with the compound C12H23.4 which is the published formula for a high-grade kerosene of the form CnH1.95n. So, in the beginning, there...

I have been reading about the Stern–Gerlach experiment and found that the atoms leaving the oven in the experiment have an average energy of 2kT, rather than an energy of 3kT/2 for a gas. I can not find a reason for this higher energy myself and would like suggestions on why this seems to be...

Homework Statement Calculate the total number of atoms in 2g of oxygen gas Homework Equations molar mass no of mole The Attempt at a Solution I try to solve that by following steps but i don't know correct or not. in fact, i am so confused with mole no of mole: 2 / 16x2 mol...

Could someone please explain to me as to why the binding energy per nucleon is lower for atoms of low mass number as compared to the atoms in the middle zone of the binding energy per nucleon versus mass number graph? My conceptual issue lies in the fact that when the mass number is low the...

Homework Statement 1.If protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains? electron 2. If an atom has 43 electrons, 56 neutrons and 43 protons what is its approximate atoms mass? What is the name of this element? Technetium, 99...

Could anybody explain to me why it is that atoms desire (sorry about the personification) a lower energy state? It just occurred to me as I was studying enthalpy changes at school...

Could anyone give me a couple of sentences to what it is?

Straight forward question. What would prevent the process of a giant lump of neutrons from forming a stable nucleus?

Homework Statement If you were to count the number of carbon atoms at the rate of four each second, how long would it take you to count 6.0 grams of Carbon atoms? Homework Equations ---- The Attempt at a Solution 6.0 g Carbon x [1 mole carbon atom / (6.02 x 10^23 grams )] = 9.97x10^-24...

Homework Statement A cubic centimeter of water has a mass of 1.00g. How many molecules does it contain? How many atoms are in 1.00g ice cube? Homework Equations 1 mole=6.02 x 10^23 molecules(or atoms) 1 mole of H20= 18g The Attempt at a Solution The answers are: 3.3 x10^22...

I encountered a question in my book: a)An electron is trapped in a solid between a group of atoms where the potential is +2.8V The de Broglie wavelength of this electron is 1.2nm. Calculate i) its speed ii) its kinetic energy iii) the sum of its kinetic energy and its potential energy b)i)...

In wikipedia, I read about BEC. so I just wonder in that articles, so I write in this page. Adopt that article, " They did this by cooling a dilute vapor consisting of approximately two thousand rubidium-87 atoms to below 170nK using a combination of laser cooling and magnetic evaporative...

Why is it that when two hydrogen atoms combine together, their combined energy is less than the energy of one hydrogen atom by itself? Why wouldn't the combined energy be twice as much?

"verify that the number of atoms..." Avagadro's constant Homework Statement One mole of a substance is defined as an amount, in grams, numerically equal to its molecular mass expressed in amu. (when we refer to a chemical element and not a compound, we use the atomic mass.) Verify that the...

Isn't the distance between two atoms where nothing exists, no atoms or subatomic particles, absolute vacuum? a place where nothing exists?? I am not too educated in such physics, so please do explain what you say

Homework Statement An oxygen atom is four times as massive as a helium atom. In an experiment, a helium atom and an oxygen atom have the same kinetic energy. What is the ratio vHe /vO of their speeds? Homework Equations K=.5mv2 The Attempt at a Solution...

Hi guys i have a rather weak concept on circular motion so i wish you guys can help me. As you know when something goes round in circle, there is a net force towards the center right? If that is the case, why this force doesn't push the particle to the center causing it to spiral towards the...

Hey. I got a locked configuration of atoms, that is there positions are fixed. I would like to calculate the energy of this configuration and also the electron density. I've looked around on the internet and in some books and found that maybe Density Functional Theory (DFT) is the answer. If...

I know this question is fairly easy, but I'm completely flabbergasted by it. I'm sure it has to do with the Ionization energy, I'm just really confused by the negative values for the binding energies. Anyway here is the question. The absolute value of the binding energy of the outermost...

Homework Statement Consider two different two-dimensional arrangements, (a) and (b), of four atoms (just four!) defined as follows: (a) in which the centres of the four atoms form a square of side a_0 (b) in which the centres of the atoms form an equilateral diamond shape with angles...

I only have one example that I can find, and that's finding the diameter of a copper atom. Do most elements follow these steps? 1.) Make sure density is in kg/m^3 2.) find number of copper atoms in a 1 meter by 1 meter cube. 3.) find number of atoms in one edge(row?) of said cube. 4.)...

1. Calculate the velocity dispersion for hydrogen atoms in the solar photosphere, which has a temperature of 5800 K. 2. I know no equations to solve the problem. 3. I have no idea any method of going about solving for velocity dispersion. I would appreciate any guidance. Thanks

Homework Statement For the molecule [SIZE="5"]ICl3 I) How many lone pairs of electrons are on the central atom? II) How many other atoms is the central atom bonded to ? III) What is the molecular geometry of the molecule? IV) What is the electron-pair geometry? a) triangular planar...

Why are all atoms in constant motion? It is just a fundamental phenomena of our world? Can someone explain the theory behind this? Why does decreasing/increasing the "temperature" affect the speed (kinetic energy) of atoms? Again, can someone explain the fundamental theory behind this?

I was watching "The Universe" series talking about scram jets, and how hydrogen is one of the most common elements in the universe. After some searching I found this http://en.wikipedia.org/wiki/H-alpha" about different states of hydrogen atoms. Which made me ask what I thought to be an obvious...

the way i understand it is photons excite atoms, causing them to increase in energy. i view this increase in energy as jostling of a atom causing more movement of its proton, neutrons, electrons. i realize a photon is a particle and a wave(in limited comprehension.) so should i view the...

Hi everyone, first time poster. Considering some of the things discussed here, I apologize if my question sounds simplistic. If this Earth could be compressed so that all the empty space in atoms would disappear how big would this Earth be? My science teacher once told me that it would be...

hi all, i have a problem that has been puzzling me, when a child has been conceived where do the atoms come from that form the fetus and the baby, did the atoms that now are forming the baby exist before conception ,(leading me to think that maybe not everything is made from start dust if...

Homework Statement Iron has a mass of 7.87 g per cubic centimeter of volume, and the mass of an iron atom is 9.27 * 10^-26 kg. If you simplify and treat each atom as a cube, (a) what is the average volume (in cubic meters) required for each iron atom and (b) what is the distance (in meters)...

It is written over here http://www.particleadventure.org/electromagnetism.html that, "...the force that keeps you from falling through the floor is the electromagnetic force which causes the atoms making up the matter in your feet and the floor to resist being displaced." Can anyone explain...

How could the Oxygen atom be stripped of at least 4 electrons and excited at the least to it's 4th energy level? I came across a device which claims to do this with Solid State Lasers (LED's) and a high voltage oscillating field...Just wondering how it would work since LED's only go to...

Homework Statement I'm working a homework problem that states: A very old specimen of wood contained 1012 atoms of 14C in 1986. • How many 14C atoms did it contain in the year 9474 B.C.? • How many 14C atoms did it contain in 1986 B.C.? Homework Equations N(t) =...

if a system is made of 3 atoms with no degeneracy with energy levels of fro example 0, e, 2e would it be safe to say that the system only has three microstate or will it be 2^3 microstates. if it is 2^3 can you please explain why?

How long would it take to count all of the atoms in 12 grams of Carbon-12, If you could only count one atom per second?

How compressed are the atoms black holes are made of? Is there a limit to how much you can compress matter? It seems to me, the most you can compress matter would be until the individual subatomic particles are side by side touching each other. Are black holes compressed more than that? Are...

Does an atom ALWAYS need to be hybridized in order for it to bond to other atoms? Why or why not? In what cases does it need to be hybridized in order to bond with other atoms?

How are atoms inside a steel arranged? Ussually we can get the data about the mass share of different elements of steel and the lattice type. But the lattice only tells us where an atom is situated, not the type of the atom. Can we tell anything about the type of the atom at a certain...

What does it mean to heat an isolated atom with photons, from a hypothetical 0deg, to 100deg? What is happening in the atom's electron shells, and how long can the atom retain the heat?

Homework Statement http://www.strings.ph.qmul.ac.uk/~russo/QP/r06QPHYEX.pdf Question 3. The Attempt at a Solution I can easily derive the equation I need, which is: lamda = h/p Which after some playing around with K.E =1/2mv^2 etc we obtain: lambda (de brogile) = h/SQRT(2mKE)...

How did we know that the more common isotope of iron has 26 protons and 30 neutrons? I'm asking a general question so the iron example is just a special case. How did we know that oxygen has 8 protons? (and 8 neutrons), and also that the 8 neutrons is the most stable isotope and that there...

Hello, I am sorry to ask a relatively unrelated question. I need to know if the chemical potential of fictitious atoms like hydrogen used to saturate the dangling bonds is different from the chemical potential of hydrogen in common chemical potential tables. Regards, Sarah

Homework Statement Why can't we use perturbation theory to calculate the effect of the spin orbit interaction in hydrogen like uranium? Homework Equations The Attempt at a Solution Is it something to do with the fact that the perturbation must be small compared to the rest of the...

Homework Statement Hi, I've got the following problem: Calculate the spacing between atoms of an ideal gas at a temperature of 273K and a pressure of 1atm. Homework Equations Mean free path equation: ʎ = 1 / 4(pi)(n)(σ²) The Attempt at a Solution I first used the ideal...

Homework Statement 4Al + 3O2 = 2Al2O3 What number of O-atoms will react if 45dm3 of the gas reacts with an excess of Al? The answer is apparently: 4 atoms Homework Equations The Attempt at a Solution Using the formula n=V/Vn (or the law stating that any gas occupies 22.4dm3 at...