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When we view distant stars they appear close to each other, but there might be huge 3d space between the stars when compared with human perception. macro or micro is question of human derived units for dimension. Can physics define space or time? To avoid definition we use words like fundamental or phenomena. Considering this, answer to this question is ...

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There is no such empty space as such in an atom. The Rutherford model of particle nature is a historic model now. After Rutherford model De broglie's hypothesis came giving us the wave nature of quantic component and how it has both particle and wave nature eg. Photon. Later on Schrödingers wave equation gave us the concept of wave function and probability ...

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Ever seen a spring? They are everywhere. What kind of material would you consider incompressible? Steel? If you put a force on it (called "stress"), it will be squeezed by a certain amount (called "strain"). The ratio of the two is called "elastic modulus" (if you like big words). In fact, if you have a rod of that material, and tap one end of it, sound ...

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Atoms themselves cannot be compressed in general. Liquids are not very compressible (they are compressible) because of distances between atoms. Gases have the most distance between atoms. Liquids have very little space in-between atoms, so when you press on them, the their is not much more room to budge. Solids can budge because of there crystal ...

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Three oxygen atoms do form a molecule (look up "ozone").

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Chemical bonds occur because of the outer electron shell also known as a valence electron shell. Oxygen has six electrons and it's valence shell. An atom wants 8 electrons in its valence shell. They both decide to share two electrons. That way they both have full valence shells. NaCl works because Cl wants 1 more electron and Na wants to get 7 more. Mg needs ...

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As anna mentioned, there are non quark models which clarify exotic hadrons. In principle, they are allowed in Quantum Chromodynamics (QCD). Non-quark models predict 1.hybrid mesons: Include quark anti-quark pair and gluon. 2.Glueballs: Gluons are their own bound states. 3.Exotic hadrons as in figure below which exchange pion at low energies (couple ...

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The fact of the matter is that there are no stable mesons, that might conceivably form states bound by the strong force, as the nucleus is bound. Within the nucleus there exist virtual mesons, i.e. described as pions etc but not on mass shell To a large extent, the nuclear force can be understood in terms of the exchange of virtual light mesons, such as ...

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This is true. If for example you subject Hydrogen gas to a perfectly monochromatic 121.57 nm laser, then all that will happen is that the gas will scatter the light in all directions, glowing without increasing the temperature. Otherwise there are many different phenomena that are involved in the heat transfer of energy by radiation. For example in solids, ...

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Indeed they can. This can even be seen in a classical set of equations if the interaction between the two polarizable objects is strong enough. Take a simple 1d problem with two polarizable point particles in a line. For low polarizations, we assume a linear relation: $$p_1 = \alpha E(r_1) = \alpha (E_2 + E_{ext}) = \alpha (k p_2 + E_{ext})$$  p_2 = ...

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They taught me that in high school too (i.e., that matter is "mostly empty space.") Only thing is, it's not true. Solid matter is mostly filled with electrons. Yeah, the mass is all concentrated in the relatively tiny nucleii, but the mass is not what photons interact with, and the mass is not what defines the physical and chemical properties of ordinary ...

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Molecules aren't just sums over their constituent atoms. There's many different kinds of bonds which involve different patterns in the overlap of electron orbitals, and which affect the energy levels those electrons can occupy - I'm assuming the QP video you watched explained how "color" relates to electron energy levels. The (hydrogen-like-)atom case is ...

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The answer is that color is determined by electron transitions between different energy states. Those levels are different in molecules than they are in the component atoms where there is only a central force in atoms, whereas the multiple positive charges in molecules creates a more complex potential field for the electrons to move around within. Molecules ...

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I'll do that teacher thing and turn your question around back at you. Why isn't the spectrum of the lithium atom just the spectrum of the hydrogen atom plus the spectrum of the helium atom? And, for that matter, why is the helium spectrum not simply two copies, somehow, of the hydrogen spectrum? Why do atoms have unique spectra in the first place? The ...

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I think you're referring to the tunneling effect. If you have two states of low energy (here: single nucleus/two nuclei) with a high energy barrier in between (here: highly deformed nucleus), then it's possible to observe transitions from one state to another, even if there is insufficient energy in the system to climb the energy barrier. A non-mathematical ...

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Most fissile materials have some probability of spontaneous fission. For example in uranium-235, seven out of every billion decays are fissions. These spontaneous fissions are the reason why a critical mass of fissile material may spontaneously develop a fission chain reaction. Alpha particles incident on beryllium-9 will break the Be nucleus into two ...

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Uranium 235 is naturally radioactive, with a half life of 703.8 million years. So if you take a lump of uranium 235 there will be nuclei decaying and releasing neutrons just due to its normal decay. These neutrons will then cause other nuclei to decay, and off goes your chain reaction. So you don't need anything to start the reaction. All you need to do is ...

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At the Large Hadron Collider we have studied matter down to a length scale of about $10^{-19}$ metres, which is about a billion times smaller than an atom. All the results so far confirm our existing theories. So it seems very unlikely that an undiscovered class of small atoms exists. The size of an atom depends on well understood physical principles. At ...

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Graphene is also very thin. According to this article the force required to break a sheet of perfect graphene by pulling it apart in such a way that all bonds break at the same time is 42 N per meter. If the width of your tape is 1cm you would need to apply 0.42 N. It is not surprising that you were able to. Even if the sheet would be perfect, you would pull ...

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An atomic species defined by its number of protons (usually denoted $Z$) and its number of neutrons (usually denoted $N$) is called a nuclide. For atomic species the number of electrons is the same as the number of protons (i.e. $Z$). You are right to assume that the nuclide of a single nuclide solid will typically determine its melting point and hardness ...

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It's not even that simple, as different crystal structures of a given molecule can have different melting points, e.g. Ice-V . I don't remember enough solid-state physics to state whether any elements form different crystal structures with different melting points, but certainly, for example, the hardness of carbon depends on whether it's diamond or ...

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Atoms and molecules that have high boiling points and melting points have strong intermolecular bonds that resist form change. Therefore, to make a material win these properties, in general your you want long chained molecules.

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It depends on the probability of interaction. This probability is computed using Fermi's golden rule, and it involves the strength of the interaction and the number of allowed final states. Weaker interactions means higher probabilities of going through the atom. Some examples: Neutrinos only feel the weak interaction, so their probability of going ...

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Any sufficiently fast particle can go through the atom since the repulsing force is finite and you can prepare a projectile with a high enough energy.

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Most sub-atomic particles can. In the Rutherford gold foil experiment, alpha particles (helium nuclei) often went through atoms. Beta particles (high speed electrons) can go through paper. There are more than a billion neutrinos going through you every single day.

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My understanding of the current theory is that galaxies are moving away from each other at an accelerated rate due to dark energy repulsion--creating an expanding universe. However, within galaxies, dark matter keeps the galaxies themselves together--so much so that the outer rim of the galaxy spins at the same rate of the inner rim--meaning there must be ...

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