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Nuclear Physics
Most commonly known for its applications in nuclear energy and nuclear weapons, Nuclear Physics also has applications in medicine and archaeology. This category is for questions about the branch of physics that deals with the study of the forces, reactions, and internal structures of atomic nuclei, Nuclear Physics.
3,164 Questions
The first three are already know to you:
#1 Width
#2 Length
#3 Depth
#4 is Space/Time it is a combination of space and time, but at high energy states they can be separated.
The remaining 7 dimensions are not yet named or discovered, but string theory predict them using math. They are so small they cannot be seen, but gravity seems to work through them. They could be quantum dimensions and the reason why quantum theory has different laws than general relativity theory and larger scales.
What does an alpha decay look like?
It can be difficult to visualize something so small that it cannot be seen directly with any light-based instrument. But we can make a stab at it, so let's do that.
An atomic nucleus is tiny beyond anything we've ever seen. It's really, really small. But picture a fuzzy sphere hanging in space. (The electrons will not be part of the picture because they are far, far away on the scale in which an atomic nucleus would be visible.) There's a little vibrating fuzzy sphere, and something is happening to it. Is it changing shape in subtle ways?
A very short distance from the nucleus, we'll see a tiny fuzzy sphere appear almost out of nowhere. That's the alpha particle, and its much smaller than the nucleus. It is composed of a pair of protons and a pair of neutrons bound together. It's a helium-4 nucleus, but you may have figured that out. The reason it seems to "magically appear" near the nucleus is because the alpha particle is believed to escape the nucleus via the mechanism of quantum mechanical tunneling. In one moment, the nucleus is whole, though it is unstable, and the next instant it has lost some of its mass and the alpha particle appears. That little alpha particle has tunneled out of the nucleus and was not seen actually exiting the mass of that nucleus. We might add that the nucleus has just undergone a nuclear transformation, and we call it nuclear transmutation. Where one chemical element existed before, another one that is two atomic numbers down on the periodic table will be left.
That alpha particle, the one that slipped unseen from the nucleus, will appear, but it won't be still. It will materialize and be off in a flash. It comes away with a tremendous amount of kinetic energy. It's really moving! It will rocket out away from the nucleus and blow through the electron cloud like it wasn't even there. It's a helium-4 nucleus as we mentioned, and its a nucleus without electrons, but it is moving far too quickly to have a high probability of "capturing" any electrons from the atom from which it arose. It isn't taking any "baggage" with it. There will be some "shape changes" in the nucleus of the atom that the alpha particle left, but it ends up a bit smaller and as indistinct in our view as it was in the beginning.
Following the alpha particle farther out, we'll see that little guy slamming into air or whatever else is in its way. These "collisions" will be scattering events, and atoms will be ionized in the process. If any solid material is present, the alpha particle will pretty much be hammered into a stop. Alpha particles don't have a lot of penetrating power. A piece of paper will block them. The alpha particle will then snatch a couple of electrons from just about anywhere around it, and the "transformation" of that alpha particle into a helium-4 atom will be complete.
yes, Nuclear fission as used in nuclear power plants produces radioactive waste with long half lives. However, this creates no problems. This wastes are either confined in the spent nuclear fuel (that is stored either in wet storage or in dry storage facilities) or stored as vitrified nuclear waste.
What are the instruments used to detect radioactive materials?
RADIAC stands for Radiation Detection, Indication And Computation.
A description is given of the main types of radiation monitoring instruments, usually called "radiac" instruments, which would be required by the civil defence authorities in the event of atomic warfare. The instruments discussed include the flash dosemeter, individual dosemeter, dose-rate meter and contamination meter. In each case, an account is given of the purpose of the instrument and the performance characteristics required, and some typical designs are mentioned. The paper concludes with an appendix giving the approved specifications for each instrument discussed.
Who postulated the existence of the neutrino?
Walter Baade and Fritz Zwicky proposed the existence of the neutron star in 1934.
Antony Hewish and Samuel Okoye discovered "an unusual source of high radio brightness temperature in the Crab Nebula" in 1965, which turned out to be the Crab Nebula neutron star.
If it is found it is expected to explain the various masses of the known particles, if it is not found it might be too massive for the LHC to make. If it is proven not to exist we may have to wait for the Supersymmetry theory to explain particle masses.
What is the fundamental force which holds particles together to form protons and neutrons?
It is called the Strong Force, specifically the ResidualStrong Force. The Fundamental Strong Force is what holds quarks (which make up Protons and Neutrons) together. The Residual Strong Force is mediated by virtual mesons and has an effective range of 10^(-15) Meters and gets significatly weaker beyond this point. This is the diameter of a Lead atom's nucleus- any bigger and it will become unstable, which is why all elements greater than this are radioactive.
What was the original purpose of the atomic bomb?
The atomic bomb creates a tremendous explosion that is more powerful than regular TNT bombs and one of the by products of the atomic reaction is radiation.
Atomic and hydrogen bombs create different types of damage and effects depending on where it is exploded. If it is exploded underground it has one type of effect. If the bomb is exploded in outer space, then there is no air so the explosion is dispelled in almost pure radiation and light energy.
Answer
They were also a major scare tactic. Let's face it. If your opponent has something that can wipe out most of an entire city, aren't you going to do as they say?
How powerful is the atomic bomb?
Atomic bombs come in a wide variety of sizes. Their explosive power is usually measured in terms of an equivalent number of tons of dynamite. Smaller bombs range in the kilotons (thousands of tons) while larger bombs are in the range of megatons (millions of tons). Even a small atomic bomb is extremely powerful, much more powerful than any conventional bomb. A large atomic bomb can destroy an entire city.
Could an atomic bomb destroy the earth?
Absolutely not 100,000 cant even destroy a continent like europe. to have a bomb destroy the world it would have to weigh at least 500 petatons of tnt which is about 200 million billion tons of tnt, a lot.
An atomic war world wide with thousands of unleashed bombs would do little more to the planet earth than an ant hive does in our world.
A nuciance, but that is probably all it will be.
Life on earth as we know it would probably be at stake though.
Atomic bombs are those with the most dangerous after-effects. Radioactive fallout that will be active for 50-100 years afterwards at least. Long term effects not fully known yet.
How did Max Planck contribute to the atomic theory?
Quantum theory, the idea that energy is emitted in discrete quanta, contrary to classical physical theory.
Why do cochroaches survive a nuclear war?
Actually, it is possible. Radiologists have found that humans can safely withstand exposure to 5 rems of Radiation. A rem is the measurement of radiation dosages that will cause a measured amount of injury to human tissue. Insect researchers have found that the lethal dose for the American cockroach is 67,500 rems and for the German cockroach it is between 90,000 and 105,000 rems. The amount of radiation that cockroaches can withstand is equivalent to that of a thermonuclear explosion. However, without the waste that humans provide cockroaches would not thrive as well after the nuclear war wiped out the human species.
Your statement about cockroaches not surviving without humans is untrue. They were perfectly capable of surviving millions of years before we came along. They do not depend on us for anything. Cockroaches can and will eat anything organic. Once they are done eating the glue from the bindings of all of the books we leave behind(glue is made from animal protein), they'll move onto eating dead animals and plants. They'll be here millions of years after our species is gone. Also, it would theoretically be possible for cockroaches to survive a nuclear war if the exposure to radiation is not constant. They are about 6 to 15 times more radiation resistant than humans, since their cells are not constantly dividing like ours. So its safe to say that any roaches that are not directly exposed to the heat of a nuclear blast and are not molting (their cells divide when they molt) would be safe. That's one of those scenarios that could go either way depending on the factors.
Another answer
Cockroaches are not actually impervious to nuclear radiation. It may have a certain resistance to it due to its simple and skeletal body structure. The reason why creatures die with radiation is because of their muscles, bones, veins and marrow. So generally almost all types of insects may survive a nuclear war.
What are some solutions to the energy shortage?
The energy crisis is a reality, we rely on fossil fuels for about 90% of our energy, but these resources are not renewable, and the greenhouse gases that they produce when burned are causing global warming (although it is debateable about the other causes. The biggest of these two problems is that they are running out, our main fossil fuels: coal, oil, natural gas. Are due to run out in 2230 (coal), 2040 (oil), 2070 (natural gas). However, these figures keep changing all the time, my physics teacher said that he first started teaching that the fossil fuels were all going to run out by 1995!
These figures keep changing for multiple reasons, one of the main ones is that we keep finding more fossil fuels. However, this will still be short-lived because they are eventually going to run out. A good place for fossil fuels is hard to find, and are desperately needed (in 1913 Germany wanted to build a train that would go from Berlin to Baghdad, and it is not my place to discuss the current war with Iraq).
The alternatives to this energy crisis are few, and involve all of us doing our bit for the environment, these include: * Rely more on alternate sources of energy (e.g. geothermic, solar, biomass, hydro, nuclear) that are renewable, and will not run out within the next century (only time will tell). That way the scales will be more balanced, and both the fossil fuels will last longer and it will not come as such a shock when the fossil fuels run out. * We can recycle more, using less resources, it does not have to be that big so that it becomes a nuissance, but every little helps (not a TESCOs advert). At my school we recycle paper and plastic. * You can use less energy, just by making sure that your house is well insulated you can reduce your electircity bills and help save the planet.
What tools can detect radiation?
Geiger Counter, named after Hans Geiger, who developed the device in 1908.
Advantages and disadvantages of nuclear power plant?
Nuclear power is neither good nor bad. The way nuclear power is produced (Safety) can be good or bad, though. Nuclear power can be generated by small power plants, creates no air pollution, and is safe when done right.
What dangerous wastes are produced by nuclear power plants?
Power plants do not produce "dangerous radioactive waves" or "dangerous electromagnetic waves" or "dangerous subsonic sounds" or anything of that nature. Coal fired plants may produces some sulfur dioxide but that's about it.Nuclear power plants produce some radioactive waste but the major danger arises from the operation in the US of such plants which is aimed at producing plutonium for bombs.
How do you identify beta decay?
A sample of 187 rhenium decays to 187-omium with halflife of 41.6 billion years. If all 188 osmium are normalized isotopes.
Yes, unless there are twoisotopescoincidentallyhavingthe equal half lives.
Does a neutrino have mass what is it made of?
Yes, it has a mass - though the mass is quite small. As far as I know, the neutrino has not been found to have smaller parts.
How does the splitting of an atom in nuclear power create heat?
When the nucleus (not the atom) splits, the fragments fly off with kinetic energy. With U-235 about 200 MeV is released per fission, which is not much, but a lot of fissions are happening every second. Most of this energy goes into kinetic energy of the fragments, which are quickly stopped in the surrounding uranium fuel rods, and hence appears as heat. If you are not familiar with this energy conversion, imagine a space capsule entering the atmosphere, it is slowed down and gets very hot as a result.
Which element is the main fuel in nuclear power plants?
Uranium, typically enriched to ~3% Uranium-235.
What is the half life of metronidazole?
The half-life of metronidazole is typically around 6-8 hours. This means that it takes this amount of time for half of the drug to be cleared from the body.
What happens to an atomic nucleus when a positron is produced?
There are a handful of elements that undergo positron decay. Positron decay, called positron emission or beta decay (beta plus decay) happens in carbon-11, nitrogen-13, oxygen-15, fluorine-18, potassium-40 and iodine-121. Let's look at what's happening. In the nucleus of these isotopes, the weak force mediates the conversion of a proton into a neutron, a positron and a neutrino, and also a photon or gamma ray. In the case of carbon-11, its decay scheme will look like this: 11C → 11B + e+ + νe + 0.45 MeV The carbon-11 atom is converted into a boron-11 atom, a positron (e+), a nuetrino (ve) and the 0.45 MeV gamma ray. (The MeV is a million electron-volts.) The new element, that new atom of boron, recoils a bit from the event, and the positron and the neutrino come out at high speed (at a high kinetic energy). The gamma ray will be moving at the speed of light (for the medium through which it is passing). You'll note that since a proton in the nucleus was converted into a neutron, the atomic number changes. It goes down one. A new element forms, as was seen in this illustration. Oh, and let's not forget that since the number of protons in the nucleus went down by one, one of the electrons in the electron cloud will no longer be "held" there. It will be released and will wander off. Links can be found below for more information.
