nuclear binding energy

Examples of nuclear binding energy in the following topics:

• Nuclear Binding Energy and Mass Defect

  • Once mass defect is known, nuclear binding energy can be calculated by converting that mass to energy by using E=mc2.
  • Nuclear binding energy is also used to determine whether fission or fusion will be a favorable process.
  • For elements lighter than iron-56, fusion will release energy because the nuclear binding energy increases with increasing mass.
  • As such, there is a peak at iron-56 on the nuclear binding energy curve.
  • Calculate the mass defect and nuclear binding energy of an atom

• Binding Energy and Nuclear Forces

  • Nuclear force is the force that is responsible for binding of protons and neutrons into atomic nuclei.
  • Nuclear force is responsible for the binding of protons and neutrons into atomic nuclei.
  • Conversely, energy is released when a nucleus is created from free nucleons or other nuclei—known as the nuclear binding energy.
  • The binding energy of nuclei is always a positive number, since all nuclei require net energy to separate into individual protons and neutrons.
  • Binding energy is the energy used in nuclear power plants and nuclear weapons.

• Nuclear Reactors

  • A nuclear reactor is a piece of equipment in which nuclear chain reactions can be harnessed to produce energy in a controlled way.
  • The energy released from nuclear fission can be harnessed to make electricity with a nuclear reactor.
  • The amount of free energy in nuclear fuels is far greater than the energy in a similar amount of other fuels such as gasoline.
  • In the first step, a uranium-235 atom absorbs a neutron, and splits into two new atoms (fission fragments), releasing three new neutrons and a large amount of binding energy.
  • However, one neutron does collide with an atom of uranium-235, which then splits and releases two neutrons and more binding energy.

• Nuclear Fission

  • The strong nuclear force is the force between two or more nucleons.
  • This force binds protons and neutrons together inside the nucleus, and it is most powerful when the nucleus is small and the nucleons are close together.
  • In these nuclei, it's possible for particles and energy to be ejected from the nucleus.
  • While nuclear fission can occur without this neutron bombardment, in what would be termed spontaneous fission, this is a rare occurrence; most fission reactions, especially those utilized for energy and weaponry, occur via neutron bombardment.
  • In nuclear fission, an unstable atom splits into two or more smaller pieces that are more stable, and releases energy in the process.

• Nuclear Fusion

  • Nuclear fusion is the process by which two or more atomic nuclei join together to form a single heavier nucleus and large amounts of energy.
  • The nuclear force is stronger than the Coulomb force for atomic nuclei smaller than iron, so building up these nuclei from lighter nuclei by fusion releases the extra energy from the net attraction of these particles.
  • For larger nuclei, no energy is released, since the nuclear force is short-range and cannot continue to act across an even larger atomic nuclei.
  • Therefore, energy is no longer released when such nuclei are made by fusion; instead, energy is absorbed.
  • The binding energy per nucleon generally increases with the size of the nucleus but approaches a limiting value corresponding to that of a nucleus with a diameter of about four nucleons.

• Fusion Reactors

  • A fusion reactor is designed to use the thermal energy from nuclear fusion to produce electricity.
  • Fusion power is the power generated by nuclear fusion processes.
  • In doing so, they release a comparatively large amount of energy that arises from the binding energy, creating an increase in temperature of the reactants.
  • This is similar to the process used in fossil fuel and nuclear fission power stations.
  • Above this atomic mass, energy will generally be released by nuclear fission reactions; below this mass, energy will be released by fusion.

• Ionization Energy

  • The ionization energy of a chemical species (i.e., an atom or molecule) is the energy required to remove electrons from gaseous atoms or ions.
  • Large atoms or molecules have low ionization energy, while small molecules tend to have higher ionization energies.
  • More generally, the nth ionization energy is the energy required to strip off the nth electron after the first n-1 electrons have been removed.
  • It is considered a measure of the tendency of an atom or ion to surrender an electron or the strength of the electron binding.
  • The ionization energy of an element increases as one moves across a period in the periodic table because the electrons are held tighter by the higher effective nuclear charge.

• Other Forms of Energy

  • Thermal, chemical, electric, radiant, nuclear, magnetic, elastic, sound, mechanical, luminous, and mass are forms that energy can exist in.
  • Nuclear Energy: This type of energy is liberated during the nuclear reactions of fusion and fission.
  • Examples of things that utilize nuclear energy include nuclear power plants and nuclear weapons.
  • For example, mass is converted into energy when a nuclear bomb explodes .
  • For example, luminous energy is radiant energy.

• Alpha Decay

  • The alpha particle also has charge +2, but the charge is usually not written in nuclear equations, which describe nuclear reactions without considering the electrons.
  • Alpha decay is the most common cluster decay because of the combined extremely high binding energy and relatively small mass of the helium-4 product nucleus (the alpha particle).
  • In theory it can occur only in nuclei somewhat heavier than nickel (element 28), in which overall binding energy per nucleon is no longer a minimum and the nuclides are therefore unstable toward spontaneous fission-type processes.
  • Alpha particles have a typical kinetic energy of 5 MeV (approximately 0.13 percent of their total energy, i.e., 110 TJ/kg) and a speed of 15,000 km/s.
  • There is surprisingly small variation in this energy, due to the heavy dependence of the half-life of this process on the energy produced.

• Direct Gene Activation and the Second-Messenger System

  • Nuclear receptors function as transcription factors because they can bind to DNA and regulate gene expression.
  • Nuclear receptors can bind directly to DNA to regulate specific gene expressions and are, therefore, classified as transcription factors.
  • Type I nuclear receptors are located in the cytosol.
  • Hormone binding to the nuclear receptor results in dissociation of the co-repressor and the recruitment of co-activator proteins.
  • Upon hormone binding, the receptor undergoes a conformational change and exposes a binding site for a G-protein.