Na2S is an ionic compound because when the metal combines with nonmetal, it usually forms an ionic compound. Here, Na is a metal and S is a nonmetal. So when they combine, it forms an ionic compound.
Well, now you have got to know that Na2S is an ionic compound, but let me explain the in-depth reason why Na2S is an ionic compound.
If you are a visual learner like me, then here is a short one minute video for you.
Why is Na2S an ionic compound?
As mentioned above, you can simply remember that when the metal combines with nonmetal, the bond between them is an ionic bond.
Here in Na2S, the Na atom is a metal and the S atom is a nonmetal.
Hence the bond between them is an ionic bond.
How does the ionic bond form between Na and S?
In Na2S, there are two atoms;
Na and S.
About Sodium (Na):
Sodium atom have 11 electrons.
The electrons arrangement in Sodium (Na) is 2, 8, 1.
So the outermost orbit of Sodium atom has 1 electron.
Now Sodium is a metal and the metals are highly electropositive (that means they have the tendency to lose electrons and become positive ions.)
Hence during the chemical reaction, the Sodium atom will lose 1 electron to form a stable octet.
About Sulfur (S):
Sulfur atom have 16 electrons.
The electrons arrangement in Sulfur (S) is 2, 8, 6.
So the outermost orbit of Sulfur atom has 6 electrons.
Now Sulfur is a nonmetal and the nonmetals are highly electronegative (that means they have the tendency to gain electrons and become negative ions.)
Hence during the chemical reaction, the Sulfur atom will gain 2 electrons to form a stable octet.
What happens when Na and S combine?
When Na and S combine with each other, the electron transfer takes place from Sodium atom to Sulfur atom (i.e from Na to S).
In other words, each Sodium atom (Na) loses 1-1 electrons and the Sulfur atom (S) gains 2 electrons.
Due to this, the Sodium becomes a positive ion (Na+) and Sulfur becomes a negative ion (S2-).
Now because of the positive charge of Sodium ion and negative charge of Sulfur ion, the electrostatic force of attraction is produced between them.
This electrostatic force between Sodium ion and Sulfur ion results in an ionic bond between them.
Hence, Na2S is an ionic compound.
I hope you have understood the reason why Na2S is an ionic compound.
Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. With a desire to make learning accessible for everyone, he founded Knords Learning, an online learning platform that provides students with easily understandable explanations.
Read more about our Editorial process.