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Q1. A radioactive uncleus undergoes a series of decay according to the scheme Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. If the mass number and atoms number of A are 180 and 72 respectively, what are there number for A4?

Solution

Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '.
Q2. The ground state energy of hydrogen atom is -13.6eV (i) What is the kinetic energy of an electron in the second excited state ? (ii) If the electron jumps to the ground state from the second excited state, calculate the wavelength of the spectral line emitted.   OR  

Solution

OR
Q3. Give the mass number and atomic number of elements on the right hand side of the decay process.

Solution

The complete equation representing mass number and atomic number is given below For Polonium Z=84, A=216 For Helium Z=2, A=4
Q4.   Complete the following nuclear reactions (a) 4Be9 + 1H1 →3Li6 + ................ (b) 5B10 + Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. → Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. + ..............  

Solution

(a) 4Be9 + 1H1 →3Li6 + Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. (b) 5B10 + Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. →Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. + on1
Q5. The isotopes 8O16 has 8 protons, 8 neutrons and 8 electrons, while 4Be8 has 4 protons, 4 neutrons and 4 electrons. Yet the ratio of their atomic masses is not exactly 2. Why?

Solution

The ratio of mass of 8O16 and mass of 4Be8 is not exactly two because of difference in the mass defect/binding energy of the atomic nuclei of the two elements.
Q6. A radioactive sample contains 2.2 mg of pure Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. which has half life period of 1224 seconds. Calculate (i) the number of atoms present initially. (ii) the activity when 5μg of the sample will be left.

Solution

  (i) By definition 11g of carbon Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. contains NA = 6.023 x 1023 atoms number of atoms in 2.2 mg = 2.2 x 10-3g of Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. will be                                         = Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. (ii) Activity A = λN Half life T1/2 =Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. Activity A = Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. Where N = Number of atoms in 5μg (= 5 x 10-6g) which is equal to Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '. Syntax error from line 1 column 49 to line 1 column 73. Unexpected '<mstyle '.  
Q7. What will be the ratio of radii of two nuclei of mass number A1 and A2?

Solution

Q8. The half life period of a radioactive substance is 30 days. What is the time for ¾ th of its original mass to disintegrate?

Solution



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