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5

Short answer: of the order of a nanosecond for hydrogen for "allowed" transitions, and the emission rate scales roughly as $Z^2$, where $Z$ is the atomic number. For an oxymoronically named "forbidden" transition, these times increase to tens of milliseconds or fractions of a second. So let's elaborate: what sets these times? A point not made enough is ...


4

The answer is the same reason why a glass of water left out at room temperature will evaporate. Even though most of the particles will be below the boiling point, the equilibrium one expects is not entirely in the liquid phase. The occasional particularly energetic water molecule will vaporize, just as the occasional neutral hydrogen atom will be struck by a ...


2

You are right that the universe formed atoms much earlier (at the temperature when photons can no longer ionize the atoms, i.e. at around $T = 150,000 K$ as you point out with your order of magnitude calculation). However, photons could still scatter off these atoms. Indeed this was quite likely considering the high density of matter in the universe. The ...


0

Electron around nucleus is described by complex wave function with both real and imaginary parts.The electron is no longer described as moving around the nucleus but is found with a certain probability around the nucleus as given by the Schrodinger's equation. Here probability is a measure of chance of finding an electron over a region. If one can measure (...


1

The reason is there is no known force that is strong enough to hold it there. Electrons are quantum particles having very small mass. But we can show how order of magnitude calculations using a minimum amount of quantum mechanics (the position-momentum uncertainty principle) and mechanical energy principles lead to correct order of magnitude results for the ...


1

The probability distribution for finding a ground-state hydrogen atom's electron in some volume is given by $dP = |\psi|^2 d^3x$, where the wavefunction $\psi$ is given by $$ \psi_{n\ell m} = \psi_{000} = \frac1{\sqrt{4\pi}}\frac2{a_0^{3/2}}e^{-r/a_0} $$ where $a_0 \approx \frac12\times10^{-10}\rm\,m$ is the Bohr radius. This is the first of the ...


-3

electrons are like planets revolving around nucleus As centrifugal force and cetripetal force had same magnitudes. When netforce is 0from all directions the particle will start spinning.The same happens for electron and start revolving around the nucleus


2

The ground state of hydrogen is an S state and has an orbital angular momentum of zero. So the only magnetic moments present will be those due to the spins of the electron and the proton. These spins can either align to give a total spin of one or anti-align to give a total spin of zero. The magnetic moment is related to the total spin by: $$ \mu = g\mu_B\...


2

The force is not magnified, is the torque that is transmitted; and is not an "amplification effect" of the interaction between atoms. The only role the interactions between atoms play is to hold the lever together. And as long as the forces involved using the lever, are smaller than the internally bounding forces of the lever, it will resist the strain and ...


2

It's possible to imagine living in a different universe where most nuclei of the element with charge 1 were deuterium, and the lighter protium was the rare outlier. However, we don't live in that universe. Most of the ordinary matter in the universe is hydrogen (75% by mass) and helium (25% by mass) which has been unprocessed since the Big Bang. Deuterium ...



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