{"id":34904,"date":"2022-11-21T10:41:40","date_gmt":"2022-11-21T05:11:40","guid":{"rendered":"https:\/\/tsboardsolutions.com\/?p=34904"},"modified":"2022-11-23T16:18:57","modified_gmt":"2022-11-23T10:48:57","slug":"ts-inter-2nd-year-physics-notes-chapter-14","status":"publish","type":"post","link":"https:\/\/tsboardsolutions.com\/ts-inter-2nd-year-physics-notes-chapter-14\/","title":{"rendered":"TS Inter 2nd Year Physics Notes Chapter 14 Nuclei"},"content":{"rendered":"
Here students can locate TS Inter 2nd Year Physics Notes<\/a> 14th Lesson Nuclei to prepare for their exam.<\/p>\n \u2192 Nearly 99.9% of mass of atom is concentrated in a small volume called Nucleus.<\/p>\n \u2192 Radius of atom is nearly 10,000 times more than radius of nucleus.<\/p>\n \u2192 Volume of nucleus is nearly 10-12<\/sup> times less than volume of atom.<\/p>\n \u2192 Atomic mass unit (1u): 1 \/12th mass of 12<\/sup>6<\/sub>C atom is taken as “atomic mass unit”. Energy equivalent of 1u = 931.5 MeV.<\/p>\n \u2192 Isotopes: The nuclei having the same atomic number (Z) but different mass number (A) are called “isotopes”. Ex: 8<\/sub>O16<\/sup>, 8<\/sub>O17<\/sup>, 8<\/sub>O18<\/sup>.<\/p>\n \u2192 Isobars: The nuclei having the same mass number (A) but different atomic numbers (Z) are called “isobars”. Ex: 14<\/sup>6<\/sub>C, 14<\/sup>7<\/sub>N<\/p>\n \u2192 Isotones : The nuclei having same neutron number (N) but different atomic number (Z) are called “isotones”. Ex: 80<\/sub>Hg198<\/sup>, 79<\/sub>197<\/sup>Au.<\/p>\n \u2192 Isomers : Nuclei having the same atomic number (Z) and mass number (A) but with different nuclear properties such as radio-active decay and magnetic moments are called “isomers”. \u2192 Positive charge of nucleus is due to protons.<\/p>\n \u2192 Toted charge of electrons in an atom is (- Ze) and that of protons is (+ Ze). Where Z is atomic number.<\/p>\n \u2192 Neutron is a chargeless particle. Mass of neutron and mass of proton are almost equal.<\/p>\n <\/p>\n \u2192 A free neutron is unstable when it is outside the nucleus. Its mean life period is 1000 sec.<\/p>\n \u2192 Inside nucleus neutron is stable.<\/p>\n \u2192 Number of neutrons in an atom is (A – Z) where A is mass number and Z is “atomic number”.<\/p>\n \u2192 Volume of nucleus is proportional to mass number V \u221d A (OR) \\(\\frac{4}{3}\\)\u03c0R3<\/sup> \u221d A \u21d2 R = R0<\/sub>A1\/3<\/sup>\u00a0where RQ is a constant. R0<\/sub> = 1.2 \u00d7 10-15<\/sup> m.<\/p>\n \u2192 Density of nuclear matter is almost cons-tant. It is independent of mass number A.<\/p>\n \u2192 Density of nuclear matter \u03c1n<\/sub> = 2.3 \u00d7 1017<\/sup> kg\/m3<\/sup>.<\/p>\n \u2192 Einstein mass .energy equation: From theory of relativity mass is treated as another form of energy. Relation between mass and energy is E = mc2<\/sup>. Where c = Velocity of light = 3 \u00d7 108<\/sup> m\/s.<\/p>\n \u2192 In a nuclear reaction Law of conservation of energy states that the initial energy and, final energy are equal provided the energy associated with mass is also taken into account.<\/p>\n \u2192 Mass defect: In every nucleus the theore-tical mass (MT<\/sub>) is always less than practical mass (M). The difference of mass of nucleus and its constituents is known as “mass defect”. Mass defect \u0394m = [Zmp<\/sub> + (A – Z) mn<\/sub>] – M.<\/p>\n \u2192 Binding energy : When a certain number of protons and neutrons are brought together to form a nucleus the certain amount of energy Eb<\/sub> is released. \u2192 Nuclear force:<\/p>\n \u2192 Radioactive decay : The spontaneous disintegration of unstable nucleus is referred as “radioactivity or radioactive decay”. \u2192 Law of radioactive decay : Let N is the number of nuclei in a sample. The number of nuclei (\u0394N) undergoing radioactive decay during the time ‘\u0394t’ is given by Where \u03bb is disintegration constant or decay constant.<\/p>\n \u2192 Decay rate (R) or Activity: The total decay rate of a sample is the number of nuclei disintegrating per unit time. <\/p>\n \u2192 Half – life period (T1\/2<\/sub>): The half-life period of a radioactive nuclide is the time taken for the number of nuclei (N) to become half of initial nuclei (No<\/sub>) i.e., N = \\(\\frac{\\mathrm{N}_{\\mathrm{o}}}{2}\\).<\/p>\n \u2192 Average life time : In a radioactive substance some nuclei may live for a long time and some nuclei may live for a short time. So we are using average life time T. \u2192 Becquerel (Bq): Becquerel is a unit to mea-sure radioactivity of a substance. \u2192 Curie: It is a unit to measure radioactivity of a substance. Note:<\/p>\n \u2192 Alpha decay : In \u03b1 – decay 2<\/sub>He4<\/sup> nuclie is emitted from given radioactive substance. So mass number of product nucleus (called daughter nucleus) is decreased by four units and atomic number is decreased by two units. Equation of \u03b1 – decay is \u2192 Average life time \u03c4 = \\(\\frac{\\mathrm{T}}{0.693}=\\frac{\\text { Half }-\\text { life period }}{0.693}\\)<\/p>\n \u2192 Power of nuclear reactor P = \\(\\frac{\\text { Number of fission } \\times \\text { Energy per fission }}{\\text { time }}\\) Here students can locate TS Inter 2nd Year Physics Notes 14th Lesson Nuclei to prepare for their exam. TS Inter 2nd Year Physics Notes 14th Lesson Nuclei \u2192 Nearly 99.9% of mass of atom is concentrated in a small volume called Nucleus. \u2192 Radius of atom is nearly 10,000 times more than radius of nucleus. … Read more<\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[26],"tags":[],"yoast_head":"\nTS Inter 2nd Year Physics Notes 14th Lesson Nuclei<\/h2>\n
\n1.u = \\(\\frac{1.992647 \\times 10^{-26}}{12}\\) = 1.660539 x 10-27<\/sup><\/p>\n
\nEx: I35<\/sub>80<\/sup> Brm<\/sup>, 80<\/sup>35<\/sub>Brg<\/sup> . Here ‘m’ denotes metastable state and ‘g’ denotes ground state.<\/p>\n
\nThe energy released while forming a nucleus is called “Binding energy Eb<\/sub>“. Binding energy = \u0394mc2<\/sup>.
\nNote : We have to supply an amount of energy equals to Eb<\/sub> from outside to divide a nucleus into its constituents.<\/p>\n\n
\nWhen a nucleus undergoes radioactive decay three types of radioactive decay takes place.<\/p>\n\n
\n\\(\\frac{\\Delta \\mathrm{N}}{\\Delta \\mathrm{t}}\\) N or \\(\\frac{\\Delta \\mathrm{N}}{\\Delta \\mathrm{t}}\\) = \u03bbN<\/p>\n
\n\u2234 Total decay rate R = – \\(\\frac{\\mathrm{dN}}{\\mathrm{dt}}\\) (OR)
\nR = R0<\/sub>e\u03bbt<\/sup> (or) R = \u03bbN (activity )
\nTotal decay rate is also called activity.<\/p>\n
\n<\/p>\n
\nIf a radioactive substance ungergoes 1 disintegration or decay per second then it is called Becquerel.<\/p>\n
\nIf a radioactive substance undergoes 3.7 \u00d7 1010<\/sup> decays per second then radioactivity of that substance is called curie.<\/p>\n\n
\nA<\/sup>Z<\/sub>X \u2192 A-4<\/sup>Z-2<\/sub>X + 4<\/sup>2<\/sub>He (a-particle)<\/p>\n
\nOr
\nP = \\(\\frac{n}{t}\\) \u00d7 E<\/p>\n","protected":false},"excerpt":{"rendered":"