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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
What is the half life of the Radioisotope Na22?
The half-life of the radioisotope Na-22 is 2.6 years.
Various types of fuses mcb how they work?
From Transmission and Distribution Electrical Engineering, Third Edition
Fuses act as a weak link in a circuit. They reliably rupture and isolate the faulty circuit under overload and short circuit fault conditions so that equipment and personnel are protected. Following fault clearance they must be manually replaced before that circuit may be put back into operation. Striker pins are available on some designs such that remote alarms may be initiated on fuse operation. Miniature circuit breakers (MCBs) or moulded case circuit breakers (MCCBs) are also overcurrent protection devices often with thermal and magnetic elements for overload and short circuit fault protection. Earth leakage protection, shunt trip coils and undervoltage releases may also be incorporated in the designs. As a switch they allow isolation of the supply from the load. Normally the MCB requires manual resetting after a trip situation but solenoid or motor driven closing is also possible for remote control. This chapter describes the various types of fuse and MCB together with their different uses and methods of specification. Examples and calculations for correct selection of different applications are also given. == Table 11.1 gives a summary of different fuse types, their uses, advantages and disadvantages. Table 11.2 summarizes some current relevant standards covering fuses. There are various categories ranging from subminiature electronic and solid state device protection fuses, power types (expulsion and high rupturing capacity (HRC)) to 72 kV. {| |+ Table 11.1: Summary of fuse types ! Category |- ! Types ! Use ! Advantages and disadvantages | # High voltage fuses above... |}
What is the difference between proton and 13C for NMR?
Protons are abundant in organic molecules, which makes proton NMR more sensitive and commonly used. 13C nuclei have a lower natural abundance and are less sensitive in NMR, requiring longer acquisition times and higher concentrations for analysis. However, 13C NMR provides complementary structural information and can help in resolving complex spectra.
Three main type of ionizing radiation emitted from radioactive atoms?
Alpha radiation: this consists of fast moving helium nuclei - i.e. two neutrons and two protons. Beta radiation: this is composed of single electrons. Gamma radiation: very high frequency, high energy electromagnetic radiation.
How do photons create electrons?
Photons create electrons in two senses. In the first sense, they don't really create electrons but eject them: from a surface in the photo-electric effect or from atoms or molecules in photo-ionization. Observing the photo-electric effect was a key part of discovering quantum mechanics.
In the second sense, an electron is created together with its anti-particle, a positron, when the photon collides with another particle. Particle-antiparticle creation requires a lot more energy than "photo-ejection". This is conversion of energy into matter, in this case matter with a rest mass of just over a million electronvolts (in mass-equivalent units according to Einstein's E=mc^2). So the photon (and target particle) need to have kinetic energy of that amount for electron-positron pairs to be created.
What is the ionizing power of alpha beta gamma?
Of alpha, beta and gamma radiation, gamma radiation has the greater ability to penetrate either shielding or living tissue. The penetration issue aside, a contact source that is an alpha emitter can do more tissue damage than beta or gamma radiation. Alpha and beta radiation are particulate radiation. They involve a particle. Gamma radiation is electromagnetic radiation of high energy. Use the links below to learn more about each type of radiation and get a handle on what's up.
How long can nuclear fires burn?
Nuclear fuel can continue to react for hundreds of thousands of years. The sun, for one has been going on for billions of years. About 2 billion years ago, a natual nuclear fissile reaction began that continued for about 200,000 years.
What is the difference between radio and gamma radiation?
They are both electromagnetic energy, so it that light (he, he) they are the same. But the gamma rays are of much higher frequency, and that means shorter wavelength and higher energy. As we move up the electromagnetic spectrum from light, we go to ultraviolet (UV) light, X-rays and then gamma rays.
okay
Is down quark heavier than up quark because neutron is heavier than proton?
Yes, the down quark is slightly heavier than the up quark. However, the difference in mass between a neutron and a proton is not solely due to the difference between the down and up quarks. Other factors, such as binding energy and contributions from virtual particles, also play a role in the mass difference between the two particles.
An Palladium reactor is a mixture of magnetic Electron energy being powered by the palladium compound, to serve as a continuous power source (Electronic) and repeated by the electronic magnet which would be used to continue the pulses of energy being made through the reactor.
What radionuclide decays to Br-73 by positron emission?
Work backwards. Positron emission means (essentially) a proton decayed into a neutron/positron pair. The mass number remains the same, but the atomic number goes down one to Bromine.
Krypton has an isotope that fits this bill.
Why quarks do not have the integral charge?
Quarks have fractional electric charges because they are fundamental particles that carry one-third or two-thirds of the elementary charge. These fractional charges are a consequence of the way quarks interact through the strong nuclear force. Quarks are always found in combinations that result in integral charges when bound together in composite particles like protons and neutrons.
Identify the resulting nucleus when uranium 238 undergoes 5 successive decay series?
The resulting nucleus after uranium-238 undergoes 5 successive decay series would be lead-206. Through multiple alpha and beta decays, uranium-238 eventually stabilizes as lead-206, which is a stable isotope.
The central core of an atom that contains most of the atoms mass?
The central core of an atom is called the nucleus. It contains protons and neutrons, which account for most of the atom's mass. Electrons orbit around the nucleus in specific energy levels.
The half life of carbon 14 is?
The half-life of carbon-14 is about 5730 years. (That's 5,730 ±40 years, if more accuracy is desired.) A link can be found below for more information about radiocarbon, which is what we commonly call carbon-14.
Is a mass of 1 amu a proton neutron or electron?
First of all: the atomic mass unit is a relative number, that can tell us a bit about the 'mass of atoms' in relation to each other. Scientists introduced it because protons, neutrons and electrons have a very small mass, and with a relative scale, we could make things a lot easier. So, if we look on the Internet, we find that: Protons weigh 1.672 * 10^-27 kg. Neutrons weigh 1.675 * 10^-27 kg. Electrons weigh 9.110 * 10^-31 kg. This is the absolute mass these three particles have. Because, however, all elements of the periodic table are composed out of these three particles, we gave them a relative weight. As such, protons and neutrons have a weight of '1', while electrons have a weight of '0'. As such, we have defined that carbon 12 (the most common isotope of carbon) has a relative mass of 12,000 u (u is here the atomic mass unit). Carbon 12 exists out of 6 protons, 6 neutrons and 6 electrons. Since electrons aren't on the relative scale, this scale is far from perfect. Also, as Einstein proved, there is a 'mass defect' (about which you should read on Wikipedia), which explains why hydrogen (and other elements ofcourse) doesn't have an atomic mass of exactly 1 u. If you can do the maths, a proton in carbon 12 doesn't have the exact weight of 1 u. So the answer is no. A different way of seeing this is looking at your periodic table. As you can see, hydrogen has a mass of 1.006 (or 1.007) u. Hydrogen has only 1 proton and 1 electron, so even without the electron the mass is still over 1.000 u.
Example of weak nuclear force?
That is not something you encounter in your "daily life", unless you work in some very specific research area. The weak nuclear force plays a role in the breaking apart of some radioactive nuclei.
Which factors have the greatest influence of radioctive decay?
The two main factors influencing radioactive decay are the type of radioactive isotope being used and the half-life of the isotope. Different isotopes decay at different rates, with shorter half-lives leading to quicker decay. Other factors like temperature and pressure can also influence decay rates to a lesser extent.
The collision of one electron and one positron produces one or two photons?
This supposition is not true. Mutual annihilation, which occurs when a positron combines with an electron, will result in the conversion of all of the mass of both particles into energy. And this will result in the formation of two photons. The production of the photon pair is the result of conservation laws, and the two photons leave the event in opposite directions. Use the related link below to learn more.
Why is carbon better than lead as a moderator in nuclear reactors?
The best moderators are those with atomic masses close to the mass of the neutron itself, maximizing the energy transferred from the neutron to the atom in every collision. Deuterium is the best moderator, with heavy water a close second. Oxygen trails well below that in third, with carbon a close fourth. Beryllium is fifth, but is far too expensive to use. Ordinary water is sixth, followed very closely by ordinary hydrogen. Other elements are practically ineffective as moderators as the mass difference is far too large and neutrons either bounce off their nuclei without slowing or get absorbed (boron has a small enough mass to slow neutrons but absorbs neutrons too easily, it is used in control rods not as a moderator).
Many compounds of the above listed elements are also good moderators and typically better than simple mixtures of identical ratios of those elements (for complex physical reasons). For example organic compounds (e.g. hydrocarbons) work good due to the carbon hydrogen present. In fact the body's of living things (e.g. plants, animals, fungi) act as good enough moderators that they have contributed to some criticality event accidents in nuclear research and the nuclear industry.
Matter attracts other matter does antimatter will repel the antimatter?
Antimatter observes and obeys the same fundamental forces that matter does:
- gravity
- electromagnetism
- weak interactive
- strong interactive
A positron, which is the anti-particle of the electron, for example, has the same mass as an electron and experiences the same attraction to all other matter (gravity) as an electron. That same positron is repelled by positively charged particles and attracted to negatively charged particles (electromagnetism).
What is radioactive material and why is it harmful?
Radiation poisoning, also called "radiation sickness" or a "creeping dose", is a form of damage to organ tissue due to excessive exposure to ionizing radiation. The term is generally used to refer to acute problems caused by a large dosage of radiation in a short period, though this also has occurred with long term exposure. The clinical name for "radiation sickness" is acute radiation syndrome (ARS) as described by the CDC. A chronic radiation syndrome does exist but is very uncommon; this has been observed among workers in early radium source production sites and in the early days of the Soviet nuclear program. A short exposure can result in acute radiation syndrome; chronic radiation syndrome requires a prolonged high level of exposure. The use of radionuclides in science and industry is strictly regulated in most countries (in the U.S. by the Nuclear Regulatory Commission). In the event of an accidental or deliberate release of radioactive material, either evacuation or sheltering in place will be the recommended measures. Radioactive waste comes from a number of sources. The majority of waste originates from the nuclear fuel cycle and nuclear weapons reprocessing. However, other sources include medical and industrial wastes, as well as naturally occurring radioactive materials (NORM) that can be concentrated as a result of the processing or consumption of coal, oil and gas, and some minerals.
source: wikipedia
Florecio Medina Sr. is know as the father of the nuclear research. He became an excellent teacher, a writer of books in mathematics, an advocate of mental math, and was the first head of the Philippine Atomic Energy Commission (known today as the Philippine Nuclear Research Institute).
