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DESCRIPTIONNuclear Chemistry. The Nucleus. Inside the nucleus there are: Protons Neutrons The nucleus is held together by the strong nucleus force. . The Nucleus. The nucleus is not always stable! The number of protons and neutrons can influence the stability of the nucleus. - PowerPoint PPT Presentation
Nuclear ChemistryThe NucleusInside the nucleus there are:ProtonsNeutrons
The nucleus is held together by the strong nucleus force.
The NucleusThe nucleus is not always stable!The number of protons and neutrons can influence the stability of the nucleus. Usually a 1:1 ratio is stable.More than this is unstable
Certain isotopes of elements are said to be unstable, and as a result they break down radioactive. All elements with an atomic number above 82 have at least one radioactive isotope.
RadioactivityThere are three major types of radioactivity:
Composed of 2 protons and 2 neutronsA helium nucleus
Made of a single negative chargeBasically an electron
High energy photonNo massAlpha particles lost:A nucleus loses 2 protons and 2 electronsThis produces a loose alpha particle and an atom that is lighter with an atomic number lower by two and an atomic mass lower by 4 amus.
Types of Radioactivity
Types of RadioactivityBeta particles lost:A neutron is made up smaller particlesIn radioactive isotopes sometimes a neutron will spontaneously break apart, releasing a beta particle (electron). What remains is a proton
The neutron breaks apart into a proton and an electron.
The electron is released from the nucleus and the proton stays.Types of RadioactivityGamma Rays:The most penetrating and high energy type of radioactivity. Large amounts of photon energy is releasedThe nucleus is unchanged in numbers of protons and neutrons, but becomes more stable.
Strength of RadioactivityAlpha particles are the most heavy but least penetrating.Gamma rays are pure energy, have no mass, but are the most penetrating.
1. Fission: This occurs when a radioactive nucleus splits to form two smaller, more stable nuclei
This can lead to dangerous chain reactions!
Nuclear Reactions1. Fission: Nuclear Reactors and Bombs
1. Fission: Nuclear Reactors and BombsA common source of Uranium-235 is used as a fuel in nuclear reactions.
It undergoes a number of reactions to release a great deal of energy, which in a reactor is harvested and used for power.
1. Fission: Nuclear Reactors and BombsAnother common source of fuel is Uranium-238
The end result of all of the reactions is a stable isotope of lead!
Nuclear Reactions2. Fusion: This type of reaction involves two small nuclei coming together to form a larger nuclei.
This is how the sun works
2. FusionNuclear fusion produces an enormous amount of energy, more than fission.
However the reaction is very unstable and dangerous.
Can only be contained in stars like the sun.