Question

The more negative the packing fraction of an element, more stable should be the nucleus. If true then 1 and if false then 0

Answer 1

The binding energy is the governing factor for the stability of the nucleus. If the energy is released in a large amount then it is more stable. The binding energy per nucleon is known as the packing fraction. The more negative is the packing fraction, more is the stability.

Step by step solution:
Binding energy is the energy that holds the nucleus together. It is predicted by the mass defect. The atom is made up of neutrons and protons and their sum is the nucleons. The nucleons govern the binding energy. The binding energy is maximum for iron in which 8.79 eV and that of hydrogen is the least.
Packing ratio/fraction is defined as the ratio of the mass defect and mass number. It is the mass defect per nucleon. The mass defect is the difference in between the isotopic mass and the mass number. If the difference is negative then the binding energy is negative. This means energy is released when the atom is being formed. Thus, the nucleus is stable and hence the statement is true.
The answer is true and thus 1.

Additional information:
Binding energy is obtained from the Einstein equation of energy i.e. E=mc2. The value has a beautiful similarity too. The elements with an even number of neutrons and protons are more stable. The element with odd odd pair is not very stable. The thing for the elements of higher mass is that there is repulsion between the positive proton and the neutrons and hence they have less binding energy.

Note: we need to be careful as selecting true as an option will not be correct. The correct answer must be 1. The binding energy is given in eV.