Electrons Definition and 998 Threads

Hello, I'm thinking about the wavelength of a freely propagating photon vs. a freely propagating electron. For the photon, we have the classical picture of oscillating E and B fields perpendicular to the direction of propagation, and we call the wavelength of the photon, which can be...

If someone is sitting in a typical living room? Would you care to elaborate, please and thank you!

Hi guys Do electrons move from high to low potential or from low to high potential I think the first one ia right because when electrons are attracted to the negative terminal they have maximum potential energy

an air wave takes place in volumes of air, water takes place in volumes of water... but u can have an electromagnetic wave go through empty space using only one particle. how does this work? this to me does not seem analogous to the waves that i am used to. does this "wave" instead refer to the...

Homework Statement Why are protons in the nucleus and electrons aren't?? The Attempt at a Solution So this is the question I was asked. I understand that protons are held together by nuclear (or strong) force. I understand that an atom is stable because there's an equilibrium...

When watching some videos about neodymium magnets, I came upon a very interesting phenomenon. Namely, the maker of the video put a large magnet near an old CRT TV. At first, a big black spot appeared on the screen. This means that the electrons were repelled from from the magnet and didn't...

Why is electron rotating in h/2pi orbit does not radiate energy

Hi everyone, This is my first post. Years ago I read in a science magazine that (at least according to a certain theory) every shell electron would be accompanied by one (or was it two?) virtual neutrino(s). At least that's my recollection of what I read. I know it sounds a little crazy. I...

Why do electrons present in spherical shaped s-orbital shield the outer electrons from the nucleus more effectively as compared to electrons present in p and subsequent orbitals? Please explain in a layman language I'm just in class 11th. :/

I have some questions about electrons flow. 1)Lets say we have a simple circuit with a metal wire and a battery supplier.Firstly if we can imagine an electrons flow in a conductive material like metal but with zero resistance and no atoms for the electrons to collide , the Fc1 force from the...

what did feynman mean when he said "positrons are electrons traveling backward in time"?

Are there any experiments or theories about the relation between magnetic dipole moment orientation and velocity vector of free electrons?

What does the term magnetic moment mean and how to look at it intellectually .what are its effects,what are its type

Ok guys, I know this must be pretty basic for but I am new to this section of physics. Anyway, my question is a two-part one, I guess: 1) Why does the spin number get only half integer values in fermions and integer values in bosons, mesons, etc.? 2) How do we conclude that the spin number is...

I just wanted to clear one thing... in metals what type of potential the electrons are subjected to..?? Is it constant , sinusoidal , square or non-periodic..?? pleasez explain a bit in accordance with free electron theory.>!

to the untrained eye electrons and protons seemed to be very different, different size, mass and composition but they have the same quantity of charge (ignoring the sign). why is this? An even more fundamental question: what is it about an electron or proton which gives it its charge in the...

What is the proof for quantisation of electrons energy around an atom?

Homework Statement Hi, this isn't a homework question but one that I think has bothered not just me... According to most sources out there an electron and a positron annihilate when they 'collide' or 'encounter' each other, however we also know that the position of an electron or positron...

Are electrons closed systems?

Hello this is my first post in this forum. I would like to ask something relatively simple and I need a simple answer please, since I am not a physics expert. Does a metal that has been red-hot heated using a flame, emit electrons? (like the electrically heated cathode of a vacuum tube does)

Hello, I know that the movement of a charged particle in space or a fluid caused by an electric field is accelerated(a = F / m) by the Coulomb force(Fc = k q1 q2 / d^2). And the Kinetic Energy of the particle is calculated through this equation ΔKE = q ΔV. But does an electron accelerate in a...

Hi, I am reading about the quantum model of the atomic structure, and recently encountered the Schrödinger’s model. However I am a bit confused about the nature of the electrons. Can we think of an electron a wave or as a particle when it is inside an atom? I know that in Schrödinger’s...

When a photon is radiated to a direct gap semiconductor and an electron is excited from valence band minimum to conduction band maximum, the applied force on the electron is zero (because k isn't changed) but the electron acquires energy. What is the source of the energy obtained by the electron...

What is the fundamental reason why the allowed energies of electrons are quantized? I did some research on the web before posting this and what I found seems to link this to the wave-like behaviour of electrons. That is, if electrons could hypothetically exist within the band gaps of the atom...

When the Lorentz force is applied on a wire that has current flowing in a magnetic field, by changing the direction of the electron(not it's KE) would this possibly change the direction of the Lorentz force? Can the wire be controlled in a way that the force's direction stays the same path?

Are electrons negative to anything? Did we notice two different charges and decide to label them like we did with left and right? I'm very curious to know why we brand electrons as negatively charged.

Homework Statement Two tiny, spherical water drops, with identical charges of -1.00 x 1016 C, have a center-to-center separation of 1.00 cm.(a) What is the magnitude of the electrostatic force acting between them? (b) How many excess electrons are on each drop, giving it its charge...

Hello all, In chemistry class we recently began the subject of nuclear chemistry. I'm sure you all know that nuclear chemistry unleashes a swarm of new particles. My teacher mentioned the Positron, a particle few of my classmates recognized. To help us understand its nature we were told to...

Homework Statement Electrons inside a carbon nanotube can be approximated as a one dimensional "particle in a box". If the nanotube is 3 micrometers long, what is the minimum speed of an electron inside the tube?Homework Equations The Attempt at a Solution The minimum occurs as n=1 so...

Homework Statement Monovalent copper (one conduction electron per atom) has a density of 9000 kg m-3 and atomic mass of 64 amu (ie. 1 kmole = 64kg). Find: a)The density of conduction electrons per unit volume b)the Fermi energy in electron volts Homework Equations f(E) =...

Suppose we have an un-charged parallel plate capacitor separated by some distance (say d). As the capacitor is not charged, the plates are in neutral position. Means, it has equal no. of electrons and protons. So, Potential difference across the plates is 0 because energy possessed by 1 C of...

Hi, I'm really confused with how electrons become 'free' in a metal. I have a few questions and would be very grateful if someone could shed some light on them. 1. Are the electrons actually free? In a sense that the atom it is attached would essentially become an ion 2. If you take a copper...

Why do atoms gain energy when they lose electrons, and why do they lose energy when they gain electrons. The only explanation I found (for the first question) raises more questions. The explanation was: it takes energy to remove an electron from an atom, and atoms gain that energy. I can...

Electrons absorbed from a photon can only be in discrete amount and match the energy difference between different energy level. However, in photoelectric effect a photon can ionize an electron and give K.E. to the electrons. As K.E. can be any arbitrary amount instead of discrete, does it mean...

I understand that a photon can be 'absorbed' by an electron resulting in the electron jumping to a higher energy level within an atom. I also understand that a photon is emitted when an electron jumps to a lower energy level within an atom. But why does the electron jump to a lower energy...

I have pictured I model about how electrons move in a circuit, What happens first is that electrons are built up on both the cathode and anode but since both of them are made of different materials, the built up electrons on one of the two poles will be more than that on the other, which...

Hi, I was wondering if 2 electrons in an 1s-orbital of a hydrogen anion (or alternatively neutral helium) are positionally dependent. By that I mean if some knowledge about one electron's position would somewhat give knowledge about the other ? Or is it completely nonsense to talk about...

Hello, I'm new here, but I've been researching this subject for several months now. I'm especially interested in the double-slit experiment performed with one electron at a time, particularly with the detection apparatus turned ON. I've found this statement, or something very much like...

Homework Statement A beam of 13.0 eV electrons is used to bombard gaseous hydrogen in ground state. What photon energies will be emitted?Homework Equations ΔE = -13.6 (\frac{1}{n^{2}_{f}} - \frac{1}{n^{2}_{i}}) However hydrogen is in the ground state therefore n_i= 1: ΔE = -13.6...

From what I understand chemical bonds arrive from the transitions of electrons between atoms and some atoms for a period of time don't have electrons. I don't understand, I thought electrons were tied to specific atoms. Any help would be greatly appreciated.

Hello All! I am having a rather difficult time locating the answer that I am seeking. What I am trying to determine is a little more understanding about resistance. I know that 1 Amp is coulombs per second, and that is 6.241×1018 electrons. I know that 1Ω is 1 Amp across 1 Volt. However what I...

If the potential difference between point A and point B is 10 Volts, then when a unit positive charge passes from A to B, the charge loses 10 J of energy. But when an electron passes from A to B does it gain energy, because in W = Q . V , Q is negative. I am really confused in potential...

Just a simple question: what happens to an electron beam in a S-G apparatus , does it split up in two spin-up/spin-down? if not, can you tell why? Thanks

I am writing out the lab for the Milikan Oil Drop experiment and punching out the numbers has shown that my measured charge is off by a factor of 5 from the theoretical amount. theoretical: 1.6e-19 experimental: 3.16e-14 See if I divide this number by 2e5 (which means I am saying there are...

I have seen this question somewhere.. I diidnt get the answer. So please help me. In how many ways three identical electrons can be arranged in two energy levels..?? Is it 2 or 4?? Here will you consider the spin of the electrons??

I was looking at a few circuit diagrams, and it seems like electrons move in the opposite direction as the electric field and current . Why is this? I don't really understand the intuition behind it.

How is electromagnetism different from gravity in that accelerated objects radiate EM waves when accelerated in an electric field but no gravitational waves are generated when objects are accelerated in a gravity field? Why do not planets orbiting the sun generate gravitational waves and...

I'm pretty sure this is a fairly obvious question, but I can't ever be sure.. So, if a photon is "scattered" 180 degrees. Its not being scattered at all, correct? So, then the energy of the "recoiling electrons" would be 0. It makes sense mathematically if I'm doing it right...

Electrons emit and absorb photons all the time. I heard that each electron is surrounded by a cloud of 10^{20} photons. That suggests to me that the rest mass of an electron must fluctuate, and that raises the prospect of uncertainty. My questions: Is the rest mass of an electron really...

What would happen i you forced two Electric currents to collide? Say we have two currents where one current flows "up" the other one "down", and they hit each other at a certain Place?