Question

What does a fluoride ion have in common with a neon atom and a sodium ion?

Answer 1

Hint : To know the common thing in a fluoride ion, a neon atom, and a sodium atom, you have to know their atomic numbers. Their charge also plays an important role in determining the common thing between the three.

Complete Step By Step Answer:
The three elements given here are a fluoride ion ${{F}^{-}}$ , a neon atom $Ne$ , and a sodium ion $N{{a}^{+}}$ .
Now, let us first state their respective atomic numbers.
Fluorine has the atomic number 9, Neon has the atomic number 10 and Sodium has the atomic number 11.
Now, as we know the atomic numbers of all three elements, we can obtain the number of electrons in fluoride ion, neon atom and sodium ion.
The atomic number does not just represent the place of the element in the periodic table, but also the number of protons and electrons in the atom.
Thus fluorine has 9 electrons, neon has 10 electrons and sodium has 11 electrons.
Now as fluoride ion has negative charge, it represents that fluorine has gained one electron to get the negative charge. Thus, fluoride ion has 10 electrons.
As, neon has been unchanged, it has 10 electrons as it had before.
AS sodium ion has positive charge, it represents that the sodium atom lost one electron to get the positive charge on it. Thus, the sodium ion also has 10 electrons.
Thus, it is now known that the common thing in all three of them is the amount of electrons.
So, the three of them are isoelectronic i.e. they possess the same number of electrons.

Note :
You have to know the atomic number of all the three elements given in the question. Also, the neon atom is unchanged because it is an inert gas. Inert elements don’t tend to react with other elements as they are already in their most stable form.