# Physics Class 12 NCERT Solutions: Chapter 13 Nuclei Part 2 (For CBSE, ICSE, IAS, NET, NRA 2023)

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Q: 4. Obtain the binding energy of the nuclei and in units of from the following data:

Atomic mass of

Nucleus has protons and neutrons

Hence, the mass defect of the nucleus,

Where,

But

The binding energy of this nucleus is given as:

Where,

Speed of light

Average binding energy per nucleon

Atomic mass of

Nucleus has protons and neutrons.

Hence, the mass defect of this nucleus is given as:

Where,

Mass of a proton,

Mass of a neutron,

But

Hence, the binding energy of this nucleus is given as:

Average binding energy per nucleon

Q: 5. A given coin has a mass of . Calculate the nuclear energy that would be required to separate all the neutrons and protons from each other. For simplicity assume that the coin is entirely made of atoms .

Mass of a copper coin,

Atomic mass of atom,

The total number of atoms in the coin

Where,

Mass number

Nucleus has protons and neutrons

∴ Mass defect of this nucleus,

Where,

Mass of a proton,

Mass of a neutron,

Mass defect of all the atoms present in the coin,

But

Hence, the binding energy of the nuclei of the coin is given as:

But

This much energy is required to separate all the neutrons and protons from the given coin.