Nuclide

What is Nuclide?

The class of atoms, characterized by their number of protons, Z, their number of neutrons, N, and their nuclear energy state, is called a nuclide. It is also known as a nuclear species. Truman P. Kohman coined this word in 1947. He defined nuclide as “a species of the atom characterized by the constitution of its nucleus” that contains a certain number of protons and neutrons. 

What are the types of nuclides?

Following are the Types of Nuclides:

• Isotopes: if the nuclides have the same proton number (atomic number) and same chemical elements but different neutron numbers, then they are called isotopes of the element. Some nuclides, particularly, are called isotopes, but nuclide is the correct term to use. Z is not fixed.

Characteristics of isotopes: an equal number of protons (Z1 = Z2)

Example:12C6, this is called carbon-12, which is the most abundant of the two stable isotopes of carbon which amounts to 98.93% of element carbon on earth.

• Isotones: they have an equal number of neutrons but different numbers of protons.

Characteristics of isotones: it has an equal number of neutrons (N1 = N2)

Example:14N7 is called natural nitrogen, which consists of two stable isotopes. It has the vast majority (99.6%) of naturally occurring nitrogen-14, with the remainder nitrogen-15. Ranging from 10 to 25, there are fourteen radioisotopes and one nuclear isomer.

• Isobars: isobars are the set of nuclides which has an equal mass number but different atomic numbers.

Characteristics of isobars: an equal mass number (Z1 + N1 = N2 + Z2)

Example:17N7, this natural nitrogen consists of two stable isotopes. It has the vast majority (99.6%) of naturally occurring nitrogen which is nitrogen-14, with the remainder nitrogen-15. Ranging from 10 to 25, there are fourteen radioisotopes and one nuclear isomer.

• Isodiaphers: they have the same neutron excess (N – Z).

Characteristics of isodiaphers: an equal neutron excess (N1 – Z1 = N2 – Z2)

Example:15N7, this natural nitrogen consists of two stable isotopes. It has the vast majority (99.6%) of naturally occurring nitrogen which is nitrogen-14, with the remainder nitrogen-15. Ranging from 10 to 25, there are fourteen radioisotopes and one nuclear isomer.

• Mirror nuclei: The number of neutrons and protons keeps changing.

Characteristics of mirror nuclei: neutron and proton number exchanged (Z1 = N2 and Z2 = N1)

Example: 3He2, this is Helium-3. It is a light, stable isotope of helium with two protons and one neutron. It is the only stable isotope of any element with more protons than neutrons other than protons. It was discovered in 1939.

• Nuclear isomers: these are the members of a set of nuclides that has equal proton number and equal mass number but has different states of excitation. 
• Characteristics of isomers: it has the same proton number and mass number but has different energy states.

Example:99Tc43, this is an isotope of titanium that decays with a half-life of 211,000 years to stable ruthenium-99, which emits beta particles but no gamma rays. This is the most significant product, long-lived fission, of uranium fission. It produces the largest fraction of nuclear waste’s total long-lived radiation emissions. 

The symbol of a nuclide is AXZ, where A represents the total number of electrons and protons and Z represents the proton. 

What Is The Difference Between Nuclides And Isotopes?

A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and neutrons. Its concept emphasizes the nuclear properties over chemical properties, whereas the isotope concept emphasizes chemical properties over nuclear properties. The number of neutrons creates a large effect on nuclear properties, but its effect on chemical reactions is negligible for most of the elements. The very lightest elements in which the ratio of neutron number to atomic number varies the most between the isotopes. 

Conclusion

Atom nuclei have protons bound together by the strong residual force except hydrogen 1H1. Protons are positively charged, so they repel each other. Neutrons are electrically neutral and thus stabilize the nucleus in two ways. First, their presence pushes protons slightly apart, which reduces the electrostatic repulsion between the protons, and so they exert an attractive nuclear force on each other and protons. That’s why one or more neutrons are necessary for two or more protons to be bound in a nucleus. The proton-neutron ratio is not only the factor that affects nuclear stability. It also depends on the atomic number, neutron number and sum.