Is an electron/proton gun possible?

In the 1944 SF story “Off the Beam” by George O. Smith, an electron gun is constructed along the length of a spaceship. In order to avoid being constrained by a net charge imbalance, it is built to also fire the same number of protons in the other direction, dissipating the mass of the “cathode”. … Read more

Is there a list of all atomic electron state transitions and the corresponding radiation emitted?

Here’s a quote from Wikipedia: As an example, the ground state configuration of the sodium atom is 1s22s22p63s, as deduced from the Aufbau principle (see below). The first excited state is obtained by promoting a 3s electron to the 3p orbital, to obtain the 1s22s22p63p configuration, abbreviated as the 3p level. Atoms can move from … Read more

Why can’t the electron enter the nucleus?

Actually, there exists an attractive force between an electron and the protons inside the nucleus, but the electron cannot be attracted towards the nucleus! What force balances that attractive force? Explain. Answer The electron is attracted by the nucleus. In the Bohr model it was said that the electron rotates around the nucleus and the … Read more

Why does a “typical” hydrogen atom have no neutron?

There are quite a few sources (mostly high-school physics textbooks) that I’ve read which don’t give the disclaimer that the hydrogen atom they are using in a diagram is an isotope (as in having unequal neutron and proton count). Why does the “typical” (in quotes due to a lack of a more scientific or precise … Read more

Is the relative atomic mass directly proportional to the size of an atom? [closed]

Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Physics Stack Exchange. Closed 8 years ago. Improve this question I have a piece of homework, i have to make a pair of models depicting pure metals and alloys. I want it … Read more

How do we know that internal conversion creates no intermediate photon?

I’ve read, from several sources, that in internal conversion — an excited electron transferring its energy to another electron which is then emitted — no intermediate gamma radiation is produced. How can we know that? Given that the distance it would travel is on the Å scale, is there any way to detect (the absence … Read more

Are atoms getting weaker? [duplicate]

This question already has answers here: Why does space expansion not expand matter? (13 answers) Closed 8 years ago. If the universe is expanding, it would make sense that the spaces between particles are getting bigger. If this is so, then the particles which make up atoms are also affected. Does that imply the spaces … Read more