Nuclear physics ppt
- 1. P.RAMYA M sc Mphil., DEPARTMENT OF PHYSICS
- 3. INTRODUCTION Atomic nucleus was discovered in 1911 by Rutherford. Size of the nucleus is 10-14 meter in diameter. All atomic nuclei are made up of elementary particles called protons and neutrons. Proton has positive charge of the same magnitude as that of on electron. Neutron is electrically neutral.
- 4. • Proton and neutron are the two different charge states. • That states are called nucleon. • Species of nucleus known as nuclide. • It is represented by ZXA Z is the atomic number. A is the mass number. X is the chemical symbol of species.
- 5. HOW TO FIND OUT THE NUMBER OF NEUTRONS • N= Number of neutrons = A-Z For example 17cl35has Z=17 Protons, A= 35 nucleons and N=35-17= 18 neutrons
- 6. CLASSIFICATION OF NUCLEI It can be classified as follows Isotopes Isobars Isotones Isomers Mirror nuclei Isotopes Isotopes are nuclei with the same atomic number Z but different mass number A. Example 14Si28 14 Si29 Isobars Isobars are nuclei with the same mass number A but different atomic number Z. Example 8 O 16 , 7 N 16
- 7. • ISOTONES Nuclei with an equal number of neutrons. For example: 6c14, 7N15, 8o16 • ISOMERS There are atoms, which have the same Z and same A, but differ from one another in their nuclear energy states. • Mirror nuclei nuclei having the same mass number but with the proton and neutron number interchanged. For example: 4Be7 (Z=4 and N=3) 3Li7 (Z=3 and N=4)
- 8. GENERAL PROPERTIES OF NUCLEUS • Nuclear size Rutherford work on the scattering of α – particles showed that the means radius of an atomic nucleus is of the order of 10-14 m to 10-15 m • Nuclear mass Assumed Nuclear mass = Zmp + Nmn real nuclear mass < Zmp + Nmn Zmp + Nmn – real nuclear mass = Δm
- 9. • Nuclear density • The nuclear density ρN can be calculated from =nuclear mass/ nuclear volume Nuclear charge The charge of the nucleus is due to the protons contained in it. Each proton has a positive charge1.6×10-19 C.
- 10. • Electric power generation (nuclear fission / fusion reactors) • National Security (nuclear weapons stockpile) • Medical Diagnosis (PET, MRI) cancer treatment with proton or heavy-ion beams • Radioactive dating (geology, archeology) • Household (smoke detectors, americium-241 α-decay) APPLICATION