nuclear binding energy
(noun)
The energy required to split a nucleus of an atom into its component parts.
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
-
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.
-
Present Sources of Energy
- Present sources of energy include fossil fuels, various types of renewable energy, and nuclear power.
- The estimates for remaining non-renewable worldwide energy resources vary; the remaining fossil fuels total an estimated 0.4 YJ (1 YJ = yottajoule, or 1024 J) and the the energy available from nuclear fuels such as uranium exceeds 2.5 YJ.
- As of December 2009, the world had 436 nuclear reactors.
- Since commercial nuclear energy began in the mid 1950's, 2008 was the first year that no new nuclear power plant was connected to the grid, although two were connected in 2009.
- Nuclear (fission) power stations, excluding the contribution from naval nuclear fission reactors, provided about 5.7% of the world's energy and 13% of the world's electricity in 2012.
-
The Hydrogen Bomb
- A thermonuclear weapon is a nuclear weapon designed to use the heat generated by a fission bomb to compress a nuclear fusion stage.
- This indirectly results in a greatly increased energy yield, i.e., the bomb's "power."
- Oddly, in most applications, the majority of its destructive energy comes from uranium fission, not hydrogen fusion alone.
- The only two nuclear weapons that have been used were both fission-based.
- The energy released by the primary section compresses the secondary through a process called "radiation implosion," at which point it is heated and undergoes nuclear fusion.
-
The Atomic Bomb
- Atomic bombs are nuclear weapons that use the energetic output of nuclear fission to produce massive explosions.
- Atomic bombs are nuclear weapons that use the energetic output of nuclear fission to produce massive explosions.
- The immediate energy release per atom is about 180 million electron volts (Me).
- Of the energy produced, 93 percent is the kinetic energy of the charged fission fragments flying away from each other, mutually repelled by the positive charge of their protons.
- This X-ray energy produces the blast and fire which are normally the purpose of a nuclear explosion.
-
The Shielding Effect and Effective Nuclear Charge
- The outer energy level is n = 3 and there is one valence electron.
- As an approximation, we can estimate the effective nuclear charge on each electron.
- The effective nuclear charge on an electron is given by the following equation:
- What is the effective nuclear charge for each?
- Diagram of the concept of effective nuclear charge based on electron shielding.