Question

The compound unstabel nucleus `._(92)^(236)U` often decays in accordance with the following reaction
`_(92)^(236)U rarr ._(54)^(140)Xe +`_(38)^(94)Sr ` + other particles
During the reaction, the uranium nucleus 'fissions' (splits) into the two smaller nuceli have higher nuclear binding energy per nucleon (although the lighter nuclei have lower total nuclear binding energies, because they contain fewer nucleons).
Inside a nucleus, the nucleons (protonsa and neutrons)attract each other with a 'strong nuclear' force. All neutrons exert approxiamtely the same strong nuclear force on each other. This force holds the nuclear are very close together at intranuclear distances.
In the nuclear reaction presented above, the 'otter particles' might be .
A. An alpha particle, which consists of two protons and two neutrons
B. two protons
C. one proton and one neutron
D. two neutrons

Answer 1

Correct Answer - d
Nuclear reactions conserve total charge, and also conserve the total approxiamte mass. The other particles in the reaction will have mass `=236 -140-94=2`.
The other particles are two neutrons. Hence, (a) is not correct.
For nuclei, number of protons tells the charege. So, the other particles must have charge `Z` such that
`92 =54+38+Z`
`:. Z =0`
Therefore, the other particles have a total atomics mass `2` and total charge `0`. Hence, only (d) is correct.