Basic atomic physics pdf

If you do not have this programme on your computer, you can download it free of charge from here:. Email This BlogThis! Labels: Atomic and Laser Physics. No comments:. Newer Post Older Post Home. Subscribe to: Post Comments Atom. Operations Management. Operations Management Course description : This operations management course is intended to be a survey of the operating practices and pro System Programming PPT slides.

System Programming Instructor: Prof. Shie-Yuan Wang Course description: Presentation of the construction of several system software Protons are about 1, times heavier than electrons, and neutrons are about 1, times heavier than electrons.

The energy balance in the decay of a neutron is achieved by the anti-neutrino, a neutral particle that carries off surplus energy as the neutron decays. The nominal mass of an atom of an element is measured by the sum of the protons and neutrons in it. This integer is called the mass number. The nominal mass of an atom is not affected by the number of electrons, which are very light. Hence the nominal mass, based on the mass number, approximates the actual atomic mass.

The number of protons in the nucleus, which determines the chemical properties of an element, is called the atomic number. Elements are arranged in ascending order of atomic number in an arrangement called the periodic table. The term derives from the tendency to periodicity of chemical properties deriving from arrangements of electrons in atoms.

The nuclei of some elements are not stable. All isotopes of heavy elements with mass numbers greater than and atomic numbers greater than 83 are radioactive. Often, there is still excess residual energy in the nucleus after the emission of a particle or after electron capture. Some of this residual energy after radioactive decay can be emitted in the form of high-frequency electromagnetic radiation, called gamma rays.

Gamma rays are essentially like X-rays and are the most penetrating form of radiation. Each quantum, or unit, of a gamma ray or other electromagnetic energy is called a photon. Gamma rays are like light, except that they are much higher frequency electromagnetic rays.

Photon energy is directly proportional to the frequency of the electromagnetic radiation. Photons of gamma rays can damage living cells by splitting molecules apart or ionizing elements in them. Many heavy nuclei emit an energetic alpha particle when they decay. For instance uranium decays into thorium with a half-life of almost 4.

The mass number of uranium declines by four and its atomic number by two when it emits an alpha particle. The number before the element name is the atomic number and that after the element name is the mass number. The totals of the atomic numbers and the mass numbers, respectively, on both sides of the nuclear reaction must be the same. This is like balancing a chemical equation, in which the number of atoms of each element on both sides of the reaction must be equal.

In beta decay, the atomic number increases by one if an electron is emitted or decreases by one if a positron is emitted. For instance thorium, which is the decay product of uranium, in turn beta-decays into protactinium by emitting an electron:. The nuclei that result from radioactive decay may themselves be radioactive.

Therefore, some radioactive elements have decay chains that may contain many radioactive elements, one derived from the other. See Uranium Factsheet for a diagram of the decay chain of uranium The radioactive decay of nuclei is described probabilistically. Within any given time period, a particular unstable nucleus has a fixed probability of decay.

At the end of one half-life, half the original element is left, while the other half is transformed into another element. After two half-lives, one fourth of the original element is left; after three half-lives one eighth is left, and so on.

This results in the build-up of decay products. If the decay products themselves decay into other elements, a whole host of radioactive materials come into being. The decay products of radioactive elements are also called daughter products or progeny. Nuclei are tightly bound together by the strong nuclear force and each nucleus has a characteristic binding energy.

This is the amount of energy it would take to completely break up a nucleus and separate all the neutrons and protons in it. Typically, binding energy increases by several megaelectron-volts MeV for every proton or neutron added to a nucleus.

Introductory Concepts. Pages Statistical Physics. Back Matter Pages About this book Introduction This is the second edition of a well-received book. Authors and affiliations Nicola Manini 1 1.