Atoms Definition and 880 Threads

Hello PF! I am writing a scientific report about magnets, but have really no clue how magnets actually work? Research has yielded a few ideas, specifically from here and here. However, sometimes (in iron, nickel, and cobalt for example) you’ll have one or more un-paired electrons. The...

I was thinking about the forces holding atoms together. Some materials seem very, very strong. But if we take thinner and thinner slices of any material it is easy to imagine that pretty soon no matter what material it is we'll have a slice so thin it would be difficult not to tear it. So...

Hey I know atom is very small particle. But is it true that cell are made from atoms.

I have found an article about an experiment that states that gravity on a small scale doesn't experience quantum effects. Of course the headline has been catchy, so I want to ask about the real importance or relevance of the experiment. Or for short: Do the results imply any consequences on...

Homework Statement How many atoms of oxygen are present in 300 grams of calcium carbonate? molar mass of CaCO3 = 100g Homework Equations The Attempt at a Solution I don't know how to proceed. Can anyone please help me out by giving the forulae or steps on how to do this problem.

Using electrical potential energy =1/4πεo Q1Q2/r , a particle further away from nucleus has lower magnitude of energy Using coulomb's law, a particle further away from nucleus experiences weaker attraction, hence less energy is needed to maintain orbit* around that e-shell compared to a...

How can a electrons energy levels increase, and decrease in eV As atoms come together to form molecules the energy levels of electrons change in eV, but are there other ways a electrons eV can change. Can heating a material change the electrons eV level, when visible light hits the electrons...

1. Homework Statement Homework EquationsThe Attempt at a Solution I can see that in B, not all C atoms are coplanar , but for C, D and E I can't see how the carbon atoms are coplanar .. I thought they are tetrahedral?

Tell me if I get this straight; When a photon of light hits an atom and interacts with the electrons, it will only affect the electrons in the outer shell causing them to go up a state, then they will fall back down and emit that exact wavelength that was absorbed? And the photons of light...

Homework Statement Imagine if you have two charged plates which have the same magnitude but opposite in charges. If you place an uncharged object near of the positive plate what will happen? Homework Equations I don't think it depends on equations The Attempt at a Solution Okay, so If you rub...

is there a theoretical way to cut solid mater by disrupting the electron field holding atoms together

Let's say I want to determine what will happen during a chemical reaction. My current reasoning is that the electrons will be more likely to move from a less electronegative atom first. For instance, cesium is much more reactive than potassium, because its electronegativity is much lower...

Hello everyone. I am a 14 year old student and am truly fascinated by chemistry. As I tried various software, they all had a very complicated UI (User Interface) and confused me a lot as a younger student. After searching a lot, I decided to make my own chemistry software. This is the final...

I have the following program that simulates a stochastic system of 400 particles. What I want to do now is separate the 200x200 grid into 2x2 smaller grids, out of which I will calculate each probability: P_i= \frac{\sum_{\text{atoms}}}{4} and from which in each step I'll be able to determine...

This Invited Review article just came out: http://arxiv.org/abs/1603.08658 The Atoms Of Space, Gravity and the Cosmological Constant T. Padmanabhan (Submitted on 29 Mar 2016) I describe an approach which connects classical gravity with the quantum microstructure of spacetime. The field equations...

Hello, I wonder how the speed of interaction affects the energy levels in atoms. We know that electrons in atom are attracted to the protons in the nucleus through the electromagnetic force. Photon, the force carrier for the electromagnetic force, moves in empty space with the speed c (the...

So I've been told about the 2n^2 rule, and how the number of electrons held in each shell goes 2, 8, 18, 32, 50, 72, etc... But I am not aware of why shells further out from the nucleus are able to hold more electrons. Does this have something to do with spdf or energy levels? Thank you.

In a covalent bonded molecule, what is the force responsible for the molecule staying together. To my knowledge it's to do with electrons of opposite spins and being at a lower energy with valence shells filled but what is the force itself that pulls a second atom along if the atom it's bonded...

This effect can be seen in the short film "A Boy and His Atom". I had a couple ideas about what this could be but I am curious if someone knows better.

what is wave and how electrons show wave phenomenon within an atom. like in Px or Py or Pz orbital how electrons interchanged from one dumble to another?

what is wave and how electrons show wave phenomenon within an atom. like in Px or Py or Pz orbital how electrons interchanged from one dumble to another?

I came across a rather dubious question that a teacher had put in a power point. It said something like,"Given a sample of 100 atoms of isotope x, after one half life of the said isotope, how many atoms of the original isotope will be left?" My answer was that it was a trick question because...

Hey all, I am looking to make a simple atom and molecule simulator for a side project, I know it obviously has no hope of being 100% accurate due to my lack of degree in physics and processing power restrictions. So far I have made them bond according solely to valence rule (which I know its a...

Homework Statement What is the Vrms, in meters per second, for helium atoms at 4.8 K? (which is close to the point of liquefaction) Homework Equations Vrms= √(3RT)/(M) The Attempt at a Solution R=3.145 T= I think its 4.15 Kelvin? based on the point of liquefaction of helium being -269°C...

A quote from wikipedia: "At sufficiently low temperatures, free protons will bind to electrons. However, the character of such bound protons does not change, and they remain protons. A fast proton moving through matter will slow by interactions with electrons and nuclei, until it is captured by...

When my eighth grade daughter was studying physics in her class, I watched a movie with her on the Hadron Collider (" Particle Fever "). We discussed atoms, electrons, protons, neutrons; we discussed orbits and statistics, and then down into the standard model and fermions, leptons, yadda...

I'm writing a paper for my teacher, not an assignment, just because I was interested in the topic. I've searched a lot of websites, but most only talk about fusing two atoms, and not saying if it is possible to fuse more than two at the same time.

I'm thinking of taking a course called Atoms, Molecules, and Solids this semester and I wanted to get a feel for the material beforehand to see if I'll like the course. If anyone could recommend a textbook based off this course description, I'd appreciate it: Quantum theory of atoms...

Ok my question: what is the difference between the binding energies of these 2 types of atoms, conceptual wise, which one is greater? I am assuming based on the easy calculations of the potential energy of the finite size atom ( inside and outside) There is a difference between the potential...

Hello everyone, I know that electrons in heavy atoms move at relativistic speeds, resulting in heavier electrons and smaller radius. If we replace an electron in a heavy atom with a muon, the muon would move to the center (occupying the lowest energy state possible), and making the radius of the...

Homework Statement Why can we assume that atoms in a solid material act like hard balls? The Attempt at a Solution because they are tightly packed together when in a solid state[/B]

Multiple_Authors submitted a new PF Insights post Why Don’t Electrons Crash into the Nucleus in Atoms? Continue reading the Original PF Insights Post.

Homework Statement The system is a chain of atoms in 1D length L and number of atoms N. and \epsilon_k=\hbar c_s k a) What is the density of states? b)The number of states that can be occupied (use boundary conditions) c) Determine w_d(I think this is the debye frequency) in terms of N,L,k...

Homework Statement A bottle of nail polis remover contains approximately 2.5 mol of ethyl acetate (C4H8O2) How many atoms are in the bottle? Homework Equations ? The Attempt at a Solution Would there just be 14 atoms?

Homework Statement How many moles of chlorine atoms are there in 71g? Given: mCl2=71g nCl2=1.00 mol MCl2=70.9g/mol Homework Equations ? 3. The Attempt at a Solution Not sure how to go about this question. Would it just be n multiplied by 2?

Homework Statement How many oxygen atoms are there in one molecule of oxygen gas? How many oxygen atoms are there in one mole of oxygen gas? Homework EquationsThe Attempt at a Solution [/B] There are 2 oxygen atoms in one molecule of oxygen gas. There is 6.02x1023 oxygen atoms in one mole of...

Homework Statement How many hydrogen atoms are there in one mole of hydrogen molecules? Homework Equations [/B] The Attempt at a Solution Is there 6.02x1023 hydrogen atoms in one mole? Is that correct?

Homework Statement https://www.google.se/search?q=f%C3%A4ltlinje&rlz=1C1_____enSE665SE665&espv=2&biw=1366&bih=643&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMI9dTNgquLyQIVhJIsCh1NxQZU#tbm=isch&q=physics+field+lines&imgrc=rKecBAfLOMsOoM%3A Why are the field lines on the positive atom pointed...

I'm interested in finding the polarizability of NaCl. Let's say I have the polarizability of ##Na^+## and of ##Cl^-##. Can I sum these to get the polarizability of NaCl, that is: $$\alpha_{NaCl} = \alpha_{Na^+} + \alpha_{Cl^-}$$ Honestly, that does seem very accurate, but perhaps it's to a...

Homework Statement Potassium 44 (4419K) has a half-life of 20 minutes and decays to form 1420Ca, a stable isotope of calcium. (a) How many atoms would there be in a 10 mg sample of potassium 44? (b) What would be the activity of the same? (c) What would the activity be after one hour? (d) What...

I don't quite understand the defination of the high field. What is the difference between atoms in down field and high field? THANKS~

Homework Statement For large intensities, what is the maximum ratio of atoms in N1 compared with N3? I suppose this is just a bit of maths I'm struggling with, seems simple I just can't get it for whatever reason D: Working through previous question, I got to: N3= (Ip/Is) / ((Ip/Is) +1 ) N1...

1. A force is applied to an atom. What can be measured to determine the atom's mass? Explain your answer.2. No equations since this is a no-science physics course.3. I don't understand how part 1 is relating to part 2 of the question. As far as I know a spectrometer is used to determine an...

If all fundamental particles are zero dimensional, are atoms empty space? And they are zero dimensional, does that mean that we don't exist?

Homework Statement Consider a balloon filled with helium gas at room temperature (T = 294 K) and atmospheric pressure. Calculate (a) the average de Broglie wavelength of the helium atoms and (b) the average distance between atoms under these conditions. The average kinetic energy of an atom is...

I am trying to understand the concept of interatomic spacing. Below is a link to three pictures, and my questions is: why are they different? I thought atoms were packed together touching each other like in the first picture but the second and third imply otherwise. Any explanation or help is...

Hi. I am currently calculating PDOS of oxygen atoms in cubic phase of BaTiO3 using Abinit package. In cubic phase the 3 oxygen atoms in the primitive cell of BaTiO3 are identical and related by space group symmetry. Should I expect exactly the same PDOS diagrams for all three oxygen atoms? I...

Here's the question: The structure of 1,3-butadiene is usually written as H2C=CH–CH=CH2. The average bond lengths given in Table 9.2 in my textbook are: C–C of 154 pm and C=C of 133 pm. Explain the fact that the observed value of the distance between the two central carbon atoms in...

Do just electrons emit photons/radiation. Or do atoms and molecules emit photons as well? Just can't get a clear answer on this. And if atoms and/or molecules also emit photons, can you please explain what causes them to?

Hi everyone: This concept has bothered me for a while. The concept being that two oppositely charged particles (electron and proton) are attracted to each other, but the electrons go on a orbital trajectory around the nucleus instead of directly "sticking to" the nucleus. The closest I have...