chapter on physics

4. Rutherford through his experiment showed that the positive charge of an atom is concentrated at the centre of the atom. Nucleus contains a positively charged and charge less particles called proton and neutron . Collectively represented as nucleons. The number of electrons or protons in an atom is called Atomic number. Which is donated as Z. The total number of protons and neutrons in an atom is called its Mass number denoted by ’A’. If there are ‘n’ neutrons in the nucleus then A=Z + n. NUCLEI

5. Goldstein modified the discharge tube & used a perforated cathode to discover a new kind of rays called ‘canal rays’. the rays were travelling in straight lines opposite to the direction of motion of the electron. They emerged the cathode through a hole or canal in it. So they are called canal rays. When a deflected beam of canal rays are found they were positively charged particles & hence they are called POSITIVE RAYS . POSITIVE RAYS

6. POSITIVE RAY EXPERIMENT

8. The Bainbridge mass spectrograph is used to find the specific charge and hence the mass of positive ions. This instrument sorts out a mixed stream of ions according to their atomic weight .

10. WORKING OF SPECTROGRAPH

13. ISOTOPE OF CARBON

16. PROPERTIES 1:- Neutron is a fundamental particle , except hydrogen all other elements contains neutron 2:- Neutron has no charge and hence is not deflected in electric and magnetic fields. 3:- Its penetrating power is high and its ionizing power is low. 4:- In free state neutron is unstable. 5:- Neutron produce intense biological effect.

18. NUCLEAR FORCE

20. EXCHANGE NUCLEAR FORCE

21. GRAPH OF NUCLEAR FORCE

25. Nuclear charge :- Ze, where Z is the atomic number and e the charge of the electron Nuclear mass :- Mass of proton + Mass of neutron. Size and shape of nucleus :- It is not only spherical. But apart from spherical nuclei can have different shapes. The shapes are decided by energy states. Density of nucleus :- Density of nucleus is very large of the order of 10^17 kg/m^3. Nuclear spin :- It has angular momentum due to the rotation inside the nucleus and spinning motion about their own axes. The nucleons have magnetic moment. For its motion. Nuclear energy states :- The nucleus can make transition from higher energy state to lower energy state. As it has discrete energy state CHARACTERISTICS OF NUCLEUS

28. GRAPH OF PACKING FRACTION

32. BINDING ENERGY GRAPH