Question

What is isostere and isodiapher?

Answer 1

There are many chemical compounds, molecules, elements and atoms. Some of these atoms have similarities in their physical and chemical properties. There are two similarity terms between these atoms which are known as isostere and isodiapher. We will see in detail what types of atoms or molecules are considered to be isosteres and isodiaphers. We will also see the properties of isosteres and isodiaphers.

Complete answer:
We know that there are several discovered chemical compounds, molecules, elements and atoms. Some atoms or elements have similarities in their electronic configuration, valence shell electrons, physical and chemical properties.
We can define isostere as the molecules or ions that have a similar shape and often have similar electronic properties. One of two or more substances that show similarity in certain properties due to the same number of total electrons or valence electrons in the same arrangement, and are composed of different atoms and do not necessarily have the same number of atoms . For example: Consider neon, the noble gas at the end of the second row of the periodic table. On its left, fluorine has one electron less than neon. If fluorine ionizes and loses one electron, it will acquire an electron to become ${F^ - }$ , which is an isostere of Ne.
Isodiaphers are atoms with different atomic number and mass number, but the same difference in neutron number and proton number. For example, the nucleus of uranium has $92$ protons and $146$ neutrons, so the difference is: $146 - 92 = 54$
The nucleus of thorium has $90$ protons and $144$ neutrons, so the difference is: $144 - 90 = 54$ .

Note:
The mass number of any element is the sum of the number of protons and neutrons, and the atomic number of any element is that the number of protons in the atom is equal to the number of electrons. The nucleus undergoes nuclear reactions such as fission and fusion, splitting or combining to produce new atoms, generating a lot of energy.