0
The neutron absorption cross section of an atom is the size of the target presented by that atom to an incoming neutron. Let's look at a couple of things and we'll get to it. Ready? Let's go.
There is a funny group of rules associated with the way an atomic nucleus reacts to an incoming neutron. It isn't necessarily like breaking a rack of billiard balls like in so many science shows. It's more like the neutron manages to press up against the nucleus and the nucleus captures it. Then what happens, happens.
One of the concepts to be considered is the energy of the incoming neutron. How fast is it going? Faster isn't necessarily better for increasing the probability of capture. It usually isn't. Another factor is the size of the target that a given nucleus presents to that neutron. We call that a neutron absorption cross section, and it's measured in barns. (Yes, like the broad side of a barn, as in hitting the broad side of a barn. And who said physicists weren't funny and couldn't make jokes!) There are tables to look this stuff up on because each given isotope of each given element has a given neutron capture cross section. That makes things challenging. And the actual cross section is different for different energies of neutrons. That ups the challenge for investigators even more.
The neutron absorption cross section of an atom is a measure of how likely an atom is to absorb a neutron when it collides with one. It provides information on the probability of a neutron being absorbed by the nucleus of an atom. The units for neutron absorption cross section are typically in barns (1 barn = 10^-24 cm^2).
Add your answer:
Earn +20 pts
What heappens to an atom that experiences radioactive decay?
Electron capture is the absorption of an electron by an atomic nucleus if that nucleus is neutron poor. An electron is captured, usually from an inner electron shell of that atom, and it will convert a proton in the nucleus into a neutron. We know that a neutron is converted into a proton and an electron in neutron decay, so it might be looked at as something of an opposite nuclear reaction where a proton and an electron combine to form a neutron.
CAN AN ATOM EXIST WITHOUTA NEUTRON?
yes, H-1 atom has no neutron
What does the absorption spectrum of an atom show?
The absorption spectrum of an atom shows that the atom emits that spectrum which it absorbs.
Is a neutron smaller than an atom?
Yes, a neutron is smaller than an atom. Neutrons are subatomic particles found within the nucleus of an atom, along with protons, and are about the same size as protons. Atoms consist of a nucleus made up of protons and neutrons, surrounded by electrons in orbit.
What happens when a neutron hits a large uranium nucleus?
One thing that can happen when a neutron interacts with a uranium atom is called scattering. The neutron "bounces off" the uranium. Aside from scattering, a neutron has a possibility of being absorbed by the uranium nucleus, and this can cause several different reactions, depending on which isotope of uranium is involved in the reaction. It is neutron absorption that is the mechanism utilized in the chain reactions in nuclear weapons and in nuclear reactors. Nuclear fuel, which is often uranium-235, fissions by absorbing a neutron. In the case of uranium-238, we make plutonium by getting that isotope to absorb a neutron. There is a lot more to learn, and you'll find related links below to get you going.
How do you calculate absorption of the elements for neutron?
Absorption of neutrons by an element depends on neutron cross-section data for that element at the energy of interest. The absorption cross-section gives the probability of a neutron being absorbed by an atom of the element. Measuring the absorptions at a certain neutron energy can help in determining the propensity of an element to absorb neutrons at that energy level.
How do nuclear fusion and nuclear fission work?
The absorption of a free moving neutron by the atom's nucleus
Where do you find a neutron in a atom?
you can find the neutron in the center of an atom.
What heappens to an atom that experiences radioactive decay?
Electron capture is the absorption of an electron by an atomic nucleus if that nucleus is neutron poor. An electron is captured, usually from an inner electron shell of that atom, and it will convert a proton in the nucleus into a neutron. We know that a neutron is converted into a proton and an electron in neutron decay, so it might be looked at as something of an opposite nuclear reaction where a proton and an electron combine to form a neutron.
Explanation of fast neutron and slow neutron in nuclear reaction?
Free neutrons are said to have a speed or a temperature. Both ideas mean pretty much the same thing, which is that they have an amount of energy associated with them. It is specifically measured most commonly, perhaps, in electron volts (eV), or as Million electron volts (MeV). Unfortunately, what is meant by fast or slow depends on the application, and perhaps the author or speaker. Free neutrons come from different sources and have different speeds when they are produced. As they fly about, they hit the nuclei of atoms, and may bounce, imparting some part of their energy to the atoms if they do. As time passes, they lose energy in this manner getting slower and slower. Please note, however, that not much time usually passes, because the half life of a neutron is a bit less than fifteen minutes. There are other things that neutrons can do besides bounce. They can cause decay of a radioactive atom, they can cause fission of a fissionable atom, and they can be absorbed. There is a likelihood of any of these events happening by the collision of a neutron with an atom, and the likelihood depends on several things. Of great importance is the isotope of the atom; different isotopes have different cross sections, the cross section being a measurement of how likely it is for the neutron to interact with the atom. Also very important is the temperature of the atom, and the speed of the neutron. The cross section of the atom will be greater or less depending on the speed of the neutron and the temperature of the atom, but not in a way that is easily predictable. A faster neutron might not cause fission as easily as a slower one in a given situation. The data on the nuclear cross sections of atoms by isotope, temperature, and neutron speed, were largely obtained empirically.
What is smaller an atom or an atom's neutron?
The neutron is a part of the atom, therefore it is smaller.
In nuclear fission reactions what causes the atom's nucleus to become unstable?
the absorption of a free-moving neutron by the atom's nucleus
CAN AN ATOM EXIST WITHOUTA NEUTRON?
yes, H-1 atom has no neutron
Can a atom exist without a neutron?
yes, H-1 atom has no neutron
CAN ATOM EXIST WITHOUT NEUTRON?
yes, H-1 atom has no neutron
How can a charged atom attract a neutron?
A neutron has no charge, so a charged atom (ion) cannot attract a neutron.
CANAN ATOM EXIST WITHOUT NEUTRON?
yes, H-1 atom has no neutron
