Nuc .

1. Nuc.

2. Assignment • Page limit 2 pages – in A4 size, Single-spacing • Topics will be distributed later. • Individual reports and no copy-paste. • Submit in soft-copy – no need to print. • Submission date: 25May, 2013 • Use LaTex – Use template of http://ijcvsp.com • Must provide referencing. - Example of an academic paper or write-up - If you have any choice of topic – let me know

3. 1.1 Atomic Mass Unit [AMU] • The unified atomic mass unit (also known as amu, symbol: u) or dalton (symbol: Da) is the standard unit that is used for indicating mass on an atomic or molecular scale (atomic mass). • It is defined as one twelfth [1/12] of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state [C-12 atom has six protons and six neutrons in its nucleus.] • That's about the mass of one proton or neutron.

4. … differentiate between, various isotopes of elements. E.g.,  uranium-235 (U-235) has an AMU of approximately 235, • while uranium-238 (U-238) is slightly more massive. The difference results from the fact that U-238, the most abundant naturally occurring isotope of uranium, has three more neutrons than U-235, an isotope that has been used in nuclear reactors and atomic bombs.

9. Neutron, Proton

11. 1.2 Stable Nucleus • The nucleus is the very dense region consisting of protons and neutrons at the center of an atom. • It was discovered in 1911, as a result of Ernest Rutherford's interpretation of the famous 1909 Rutherford experiment performed by Hans Geiger and Ernest Marsden, under the direction of Rutherford. • The branch of physics concerned with studying and understanding the atomic nucleus, including its composition and the forces which bind it together, is called nuclear physics.

12. Rd. - Makeup • The nucleus of an atom consists of protons and neutrons bound by the nuclear force (also known as the residual strong force). • These p/n are further composed of subatomic fundamental particles known as quarks bound by the strong interaction.

13. Rd. • Protons and neutrons are fermions, with different values of the isospin quantum number • So two protons and two neutrons can share the same space wave function since they are not identical quantum entities. • They sometimes are viewed as two different quantum states of the same particle, the nucleon. • Two fermions, such as  two protons, or  two neutrons, or  a proton + neutron (the deuteron) can exhibit bosonic behavior when they become loosely bound in pairs.

14. Rd. • Fermions  any particle characterized by Fermi–Dirac statistics and following the Pauli exclusion principle; fermions include all quarks and leptons, as well as any composite particle made of an odd number of these, such as all baryons and many atoms and nuclei. • Bosons  which obey Bose–Einstein statistics.

15. 1.3 Binding energy Play from – http://www.ndt-ed.org/EducationResources/HighSchool/Radiography/stableunstableatoms.htm • E is close to P: mix • E is close to E – depart • 2 Electrons – both neg charge – so their lines of force are repelled • 2 Ps – both positives – repelled • E and P  their lines of force bend towards each other

16. A force called the strong force opposes and overcomes the force of repulsion between the protons and holds the nucleus together. • The energy associated with the strong force is called the binding energy. • The electrons are kept in orbit around the nucleus because there is an electromagnetic field of attraction between the positive charge of the protons and the negative charge of the electrons.