Classify each of the following nuclides as probably stable, beta-emitter or positron-emitter. Ca 20 49 , Hg 80 195 , Pb 82 208 , 5 8 B , Ho 67 150 , Al 13 30 , Sn 50 120 , Kr 36 94

The nuclides near the belt of stability are probably stable. Those above the belt are beta-emitters, since the neutron proton or n p ratio is high. Those below the stability belt are positron-emitters, since the neutron proton or n p ratio is low. The stable nuclides are Pb 82 208 and Sn 50 120 . The beta-emitters are Ca 20 49 , Al 13 30 and Kr 36 94 . The positron-emitters are Hg 80 195 , 5 8 B and Ho 67 150 .

Classify each of the following nuclides as probably stable, beta-emitter or positron-emitter. Ca 20 49 , Hg 80 195 , Pb 82 208 , 5 8 B , Ho 67 150 , Al 13 30 , Sn 50 120 , Kr 36 94

The nuclides near the belt of stability are probably stable. Those above the belt are beta-emitters, since the neutron proton or n p ratio is high. Those below the stability belt are positron-emitters, since the neutron proton or n p ratio is low. The stable nuclides are Pb 82 208 and Sn 50 120 . The beta-emitters are Ca 20 49 , Al 13 30 and Kr 36 94 . The positron-emitters are Hg 80 195 , 5 8 B and Ho 67 150 .

Of the three isobars, Cd 48 114 , 49 114 In and Sn 50 114 , which is likely to be radioactive? Explain your choice.

The given nuclides are having same mass number, hence, they are isobars. Nuclides that have odd numbers of protons and neutrons are the least stable and this means that they are more radioactive. The nuclides with even numbers of protons and neutrons, or nuclides containing even numbers of protons and odd numbers of neutrons and vice versa are generally stable. Cd 48 114 has 48 (even) protons and 66 (even) neutrons; stable. In 49 114 has 49 (odd) protons and 65 (odd) neutrons; unstable. Sn 50 114 has 50 (even) protons and 64 (even) neutrons; stable. Among the given nuclides, In 49 114 is having the odd number of protons and the odd number of neutrons, hence, it is likely to be radioactive. It emits hard nuclear beta-rays of energy 1 . 89 MeV .