Question

The binding energy per nucleon of iron atom is approximately:
A.$13.6{\text{eV}}$
B.${\text{8}}{\text{.8MeV}}$
C.Infinity
D.$10{\text{MeV}}$

Answer 1

Binding energy: It is defined as the smallest amount of energy required to remove a particle from a system of particles into individual parts i.e. energy required to separate the particles, is known as binding energy.

Complete step by step solution:
First of all let us talk about nucleons.
Atoms: It is the smallest unit of an element. The elements are made of the same kind of atoms. In the atoms there are three particles: electrons, protons and neutrons.
Electrons: They are the negatively charged particle having negligible mass. They move in the atoms outside the nucleus in a fixed orbit.
Protons: They are positively charged particles. They have mass. They are present in the nucleus (special room in the atoms were neutrons and protons are present).
Neutrons: They have no charge but they have mass. They are also present in the nucleus along with protons.
Atomic number: The number of protons present in an atom, is known as atomic number. It is represented by the symbol $Z$.
Nucleons: They are defined as either protons or neutrons present in the nucleus or we can say protons and neutrons are known as nucleons.
Now we will talk about binding energy.
Binding energy: It is defined as the smallest amount of energy required to remove a particle from a system of particles into individual parts i.e. energy required to separate the particles, is known as binding energy.
Binding energy per nucleon: It is defined as the average energy required to remove an individual nucleon from a nucleus or it is defined as the binding energy of the nucleus divided by the total nucleons in the nucleus.
Binding energy per nucleon is maximum for atomic number $50$ and this nuclei i.e. tin. And this nuclei is the most stable nuclei. Iron whose atomic number is $56$ is very close to the element of atomic number $50$. So its binding energy per nucleon is about $8.8{\text{MeV}}$.

So the correct answer is option B.

Note: The most stable element will be those elements which have highest binding energy per nucleon. By the graph it is clear that the most stable atom will be at the top of the graph i.e. the element having atomic number $56$.