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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 internal heat of the Earth is thought to be about 20% residual heat from planetary accretion and about 80% from radioactive decay. The internal heat provides heat to liquefy magma and send plumes of the hot material upward, through the mantle, to the surface. This material comes out from the surface in various forms, such as lava, and thus forms volcanoes.
How does knowing the half life of an isotope help a geologist establish the age of a rock or fossil?
In general, the shorter the half-life of a radioisotope, the less far back in time it will be useful in dating things from the past. Radioisotopes with short half-lives decay away more quickly, and if "too much" time has passed, there isn't a sufficient amount of the radioisotope left to "count" it with sufficient accuracy to date something. Radiocarbon dating is a fairly well known method of dating living thing back a few tens of thousands of years. It looks at ("counts") the carbon-14 decay in a sample and determines how long ago the living material died. When we are alive, our bodies are built of materials that include carbon. And carbon as it occurs has a bit of the C-14 isotope in it. That means there will be a give "concentration" of C-14 in all our tissues. When we die, C-14 intake stops, and the C-14 in our tissues decays without being replaced. We know how long it takes for C-14 to decay (we know its half-life), and we can measure what is left and make a fairly accurate estimate of how long the material has been dead. After a while, there just isn't enough C-14 left to make for accurate dating. Anyone who says living material has been C-14 dated to 100,000 years is pulling your leg. If we were dating rocks, we could use uranium-lead or lead-lead dating. They take as way back in time. But these methods have limits on their applications, just like carbon dating. There are always limits on what we can do as regards radiometric dating, and one of them depends on which radioisotope we choose to illuminate the past.
4 Explain the structure of the atom according to Rutherford?
* * * * * * * ---- were used as a probe into atomic structure by being allowed to pass through a thin piece of == == == == == == == ==
* * * * codepoint U+269B (⚛), ATOM SYMBOL, uses a Rutherford atom. * installation. * == == * * * == ==
The existence of alpha decay in radioactive uranium was first discovered by?
The existence of radiation was discovered in 1896 by Henri Becquerel in the course of experiments involving uranium salts, though the nature of it was unknown.
The nature of the alpha particle was discovered by Ernest Rutherford, and he showed it was essentially an helium nucleus in 1907.
What does a decayed atom mean?
Basically, it means that the structure of the atom has changed from a less stable state to a more stable state. Since the energy of the atom is reduced, something has to be emitted from it, whether a particle or some form of energy, usually both. Sometimes the decay requires some input from outside the atom, and sometimes it is spontaneous. There are many kinds of atomic decay.
Fission is one. In fission, the atom splits and two atoms are produced. Also a number of neutrons are emitted, and a lot of heat is produced.
Alpha decay is another. Alpha decay happens when the atom emits an alpha particle, which is essentially a helium ion moving very fast. This causes the atom to change from one element to another, the daughter element having an atomic number 2 less than that of the parent. Also, the isotope number is reduced by 4.
Beta decay is another. A beta particle is released, either positive or negative. If the beta decay is positive, it usually means a proton is turned into a neutron by capturing an electron from the atom's innermost shell; this reduces the atomic number by one, changing the element, but the isotope number stays the same and the emission is a neutrino. If the beta decay is negative, it means that an electron is emitted from the atom, then a neutron has to be converted to a proton, and the atomic number is increased by one, changing the atom to a new element; the isotope number stays the same, but the mass of the atom is reduced.
Gamma radiation is another. In gamma radiation, a very energetic photon called a gamma ray is released. This may happen at the same time as some other emission, or because of a change in the energy state of an atom, producing a different isomer. The mass of the atom is reduced very slightly, but if there is no other emission going on at the same time, the atomic number and isotope number remain the same (the more excited state is indicated by attaching a lower case m to the isotope number).
The atom might emit a neutron. This reduces the isotope number by 1.
There are other forms of decay, but these are probably the most important, and give a good idea of the sorts of things that go on.
Medical and beneficial use of neptunium?
- intermediate in the preparation of plutonium 238
- in the instruments for the detection of high energy neutrons
- possible use in the future as material for nuclear weapons
- possible use in the future as nuclear fuel
Neptunium has not a medical use.
The work done by the gas on the environment as it expands is given by the equation: (W = -P \Delta V), where (P) is the pressure and (\Delta V) is the change in volume. Since the gas expands at constant temperature, its final pressure is equal to its initial pressure. Therefore, the work done on the environment is (W = -(2x10^5 \text{ Pa}) \times (3.00 \text{ m}^3) = -6.00 \times 10^5 \text{ J}).
What would happen to a person if he became radioactive?
Actually you are radioactive. Some of the Potassium in your body is decaying by radioactivity to Argon. This is a small amount however, smaller than the radiation you'd receive from an ionization smoke detector in your house. If you take a plane flight, at higher altitudes you are exposed to charged particles from space, from which the earth's atmosphere usually shields us. So international flights are (slightly) more hazardous, for they spend more time, and at higher altitudes than do domestic ones. This amount of radiation can usually be ignored though, even by flight crew, who spend much more time at altitude than does a passenger.
Focusing closely on the question, a serious radiation dose will cause your hair to fall out, and maybe your gums to bleed. Serious enough, of course, would be fatal. Some of this is because the radiation actually changes the chemical nature of the atoms. (As above with the potassium.) Some of the daughter elements, as they are called, are at least useless, and at worst, toxic.
TNT (trinitrotoluene) is a strong explosive commonly used in military applications and mining operations due to its high explosive power and stability. It generates a large amount of energy when detonated, making it effective for various demolition and construction purposes.
Can nuclear reactions create new elements?
When atoms undergo nuclear fission , the result is always two different atoms very much less massive than the parent. For fusion, the resulting atom or atoms are usually of a different element, but not always.
Part of the trick to understanding this is that in these types of reactions, the numbers of protons and neutrons going in has to be the same as the number coming out, though some of the decay reactions other than fission turn a proton into a neutron or the other way around. Another thing to remember is that the number of protons determines the element of an atom.
FusionWhen we fuse atoms, we are taking neutrons and protons from the nuclei of the two atoms and putting them into a single daughter atom. A typical example of a fusion reaction is:12H + 12H --> 23He + 01n
In this reaction, the symbol 12H represents hydrogen (atomic symbol H), with the 2 indicating the number of protons plus the number of neutrons, and 1 being the number of protons; this can be read as hydrogen-2. Similarly, 23He is helium-3, and 01n is a silly way to represent a neutron, but it makes the balancing of the equation obvious.
We might imagine that fusion always produces an atom of a new element, but this is not the case. It is possible to fuse two helium atoms to produce a heavier helium atom plus a pair of protons, which are essentially hydrogen atoms. A reaction follows:
23He + 23He --> 24He + 11p + 11p
So two atoms of helium are combined to produce one atom of helium plus a couple of particles.
FissionAtoms have to be pretty heavy to undergo fission, which is what happens when one atom splits into two atoms. Again, the number of protons is kept the same in fission, as is the number of neutrons. But here, the parent atom has a number of protons, and the daughter atoms combine to have that number of protons. Clearly fission cannot happen without the daughter atoms being entirely different from the parent. An example equation for fission is as follows (but bear in mind that the uranium fission equation can take many different forms with many different results):92235U --> 3692 Kr + 56140Ba + 2 01n
Other types of decayThere are many other types of nuclear decay with a single atom undergoing some sort of change to produce another single atom. In most of them, the daughter atom is of a different element than the parent, but this is not true in all cases. In decay involving producing only a gamma ray, for example, there is only a slight change in the mass of the atom. For example:99mTc --> 99Tc + gamma
Quantum possibility refers to the range of potential outcomes or states that a quantum system can exhibit based on the probabilistic nature of quantum mechanics. It involves the idea that, at the quantum level, particles can exist in multiple states simultaneously until measured or observed, leading to a multitude of possible outcomes for any given scenario. Quantum possibility is a fundamental aspect of quantum theory and is a key factor in understanding the behavior of particles at the atomic and subatomic levels.
What part of that atom is involved in bonding?
The outer or valence electrons are the ones involved in bonding.
Valence electrons
What element is converted to plutonium to make the first nuclear reactors?
Uranium-238 is converted to plutonium-239 in nuclear reactors by absorbing neutrons, which then undergo fission reactions. This conversion process is a key aspect of nuclear reactor operation, particularly in breeder reactors where new fuel is produced while generating energy.
What occurs in the sun's core and generates the sun's energy?
Nuclear fusion occurs in the sun's core, where hydrogen atoms combine to form helium, releasing a tremendous amount of energy in the process. This process is sustained by the sun's gravity and high temperature, providing the energy that powers the sun and sustains life on Earth.
What role do isotopes play in nature?
Isotopes play a crucial role in nature by providing information about the age of rocks and fossils through radiometric dating, helping scientists track the movement of elements in the environment, and serving as tracers for biological and chemical processes. They also play a role in medical imaging and therapy.
I don't believe that this form of deay would directly form a X-ray photon. To go from 81RB to 81KR, a proton would need to be converted to a neutron - thus inverse Beta Decay. During this decay event, a neutrono would also be produced.
Because the electron captured is in the inner shell, the atom is unstable. Thus, when the electrons realign in their respective shells, a high energy photon would then be produced. However, this photon is not the direct result of decay but is instead due to the atom returning to is ground state.
See http://en.wikipedia.org/wiki/Electron_capture
With radioactive decay, predicting when any individual atom will decay is nearly impossible. However, when a lot a particles are present, then it is possible to get a general idea of how much will decay in a certain period of time. The half-life is this measurement, and it is the time that it takes for one halfof the substance to decay. Hence half-life or how long it takes for half to "die".
For any size sample of a substance, the half-life is how long it takes for half to be left, so for a substance with a half-life of 2 days, half of the substance will decay in two days. Therefore your answer is simply half of 30g which is 15g.
Additional reading: http://simple.wikipedia.org/wiki/Radioactive_decay
After one week, 128g of element Z will remain. After two weeks, 64g will remain. After three weeks, 32g will remain. After four weeks, 16g will remain. After five weeks, 8g will remain. After six weeks, 4g will remain. After seven weeks, 2g will remain. After eight weeks, 1g will remain. After nine weeks, 0.5g will remain. After ten weeks, 0.25g will remain.
Was there acutally a bang to be heard in the big bang?
No because then it wouldn't have been a bang.
The above information is actually incorrect, however is slightly correct in the respect that tecqnically a bang is a loud noise, the big bang should actually be called the big explosian, back to the main topic, the big "bang"would have been silent as space is a large vaccum and does not carry the waves needed to carry sound
as an example we learnt in school last year that in space if two astronaughts microphones broke they would have to phsically touch helmets to communicate as the vaccum of space would not carry the waves between particle (like on earth)
When a beta particle is ejected from a nucleus the nucleus then has greater?
When a beta particle is ejected from a nucleus, the nucleus gains one unit of positive charge as it transforms a neutron into a proton. This results in an increase in the atomic number of the atom while the mass number remains the same.
Does the half life change as a radioactive atom approaches absolute zero?
While the half-life can be affected by changes in the motion of atoms due to changes in temperature, the effect is negligible. Half-life is far more drastically affected by forces between particles within the nucleus rather than any atomic motion or atomic interactions. There may be a small decrease in decay rate as temperature decreases but it is negligible thus far. It has been proven that increases in decay rate with temperature are essentially zero.
According to the current standard model of particle interactions the effects of temperature change on decay rate can be ignored at all temperatures.
X-rays can be harmful if not used properly. Unnecessary exposure to X-rays can increase the risk of cancer due to the radiation. However, when used in medical imaging for necessary diagnostic purposes, the benefits usually outweigh the risks. It is important to follow recommendations and guidelines provided by healthcare professionals to ensure safe use of X-rays.
What is produced when uranium nuclei is bombarded with neutrons?
This depends on a lot of things.
When a neutron collides with an uranium atom, it might bounce off, cause the atom to decay, or be captured into the atom. But which it does depends on the isotope of the atom, the temperature of the atom, and the velocity of the neutron. My understanding is that it can cause any isotope of uranium to decay, and certainly it can bounce off any, but it can only be captured by U233, U234, or U235; the other isotopes of uranium, U236, and U238, will not capture neutrons.
The interactions of various isotopes of different temperatures with neutrons of different velocities is complicated, and no simple rule about it can be stated.
Name of process when protons and neutrons react during nuclear fusion?
The process when protons and neutrons react during nuclear fusion is called nucleosynthesis. This is the process by which new atomic nuclei are formed from existing protons and neutrons.
