Related InterviewSolutions

• The radioactive nuclei are unstable and emit alpha `(._(2)He^(4))` , beta `(._(-1)e^(0))` and gamma `(._(0)gamma^(0))` radiations to acheive states of greater stability. Rutherford and Soddy suggested the following rules governing the radioactive decay, (i) The algebric sum of charges (atomic numbers) before and after disintegration must be the same. (ii) The sum of mass numbers before and after disintegration must also be the same. In beta decayA. A remains unaffected, Z increases by 1.B. A is unaffected, Z decreases by 1C. A increases by 1, Z is unaffactedD. A decreases by 1, Z is unaffected.
• The radioactive nuclei are unstable and emit alpha `(._(2)He^(4))` , beta `(._(-1)e^(0))` and gamma `(._(0)gamma^(0))` radiations to acheive states of greater stability. Rutherford and Soddy suggested the following rules governing the radioactive decay, (i) The algebric sum of charges (atomic numbers) before and after disintegration must be the same. (ii) The sum of mass numbers before and after disintegration must also be the same. In alpha decayA. mass number A decrease by 4 and atomic number Z increases by 2.B. A decreases by 4 and Z decreases by 2C. A increases by 4 and Z decreases by 2D. A increases by 4 and Z increases by 2.
• Out of alpha, beta and gamma radiations, which are affected by electric field and magnetic field?
• The mass of a `a_3^7 Li` nucleus is `0.042 u` less than the sum of the masses of all its nucleons. The binding energy per nucleon of `._3^7 Li` nucleus is nearly.
• A hydrogen atom initially in the ground level absorbs a photon, Which excites it to n=4 level. Determine the wavelength and frequency of photon.
• Energy of an electron in an excited hydrogen atom is `-3.4eV`. Its angualr momentum will be: `h = 6.626 xx 10^(-34) J-s`.
• Nuclei with magic no. of proton Z=2,8,20,28,50,52 and magic no. of neutrons N=2,8,20,28,50,82 and 126 are found to be stable. (i) Verify this by calculating the proton separation energy `S_(p)` for `.^(120)Sn (Z=50)` and `.^(121)Sb =(Z=51)`. The proton separation energy for a nuclide is the minimum energy required to separated the least tightly bound proton form a nucleus of that nuclide. It is given by `S_(p)=(M_(z-1,N)+M_(H)-M_(Z,N))c^(2)`. given `.^(119)Sn =118.9058u, .^(120) Sn =119.902199u, .^(121)Sb=120.903824u, .^(1)H=1.0078252u` (ii) what does the existence of magic number indicate?
• What is the difference between a photon and a neutrino?
• Before the neutrino hypothesis, the beta process was thought to be the transition, `n rarr p+bare`. If the was true, show that if the neutron was at rest, the proton and electron would emerge with fixed energies and calculate them. Experimentally, the electron energy was found to have a large range.
• Sometimes a radioactive nucleus decays into a nucleus which itself is radioactive. An exmple is: `""^(38)"S" overset ("half-life") underset(=2.48) to ""^(38)Cl overset ("half-life") underset(=0.62h) to ""^(38)Ar ("stable")` Assume that we start with 1000 `""^(38)S` nuclei at time t=0. The number of `""^(30)Cl` is of count zero at t=0 and will again be zero at `t=oo`. At what value of t, would the number of counts be a maximum?