MgO (Magnesium oxide) is an ionic compound because when the metal combines with nonmetal, it usually forms an ionic compound. Here, Mg is a metal and O is a nonmetal. So when they combine, it forms an ionic compound.
Well, now you have got to know that MgO is an ionic compound, but let me explain the in-depth reason why MgO is an ionic compound.
If you are a visual learner like me, then here is a short one minute video for you.
Why is MgO 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 MgO, the Mg atom is a metal and the O atom is a nonmetal.
Hence the bond between them is an ionic bond.
How does the ionic bond form between Mg and O?
In MgO, there are two atoms;
Mg and O.
About Magnesium (Mg):
Magnesium atom have 12 electrons.
The electrons arrangement in Magnesium (Mg) is 2, 8, 2.
So the outermost orbit of Magnesium atom has 2 electrons.
Now Magnesium 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 Magnesium atom will lose 2 electrons to form a stable octet.
About Oxygen (O):
Oxygen atom have 8 electrons.
The electrons arrangement in Oxygen (O) is 2, 6.
So the outermost orbit of an Oxygen atom has 6 electrons.
Now Oxygen 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 Oxygen atom will gain 2 electrons to form a stable octet.
What happens when Mg and O combine?
When Mg and O combine with each other, the electron transfer takes place from Magnesium atom to Oxygen atom (i.e from Mg to O).
In other words, the Magnesium atom (Mg) loses 2 electrons and the Oxygen atom (O) gains 2 electrons.
Due to this, Magnesium becomes a positive ion (Mg2+) and Oxygen becomes a negative ion (O2-).
Now because of the positive charge of Magnesium ion and negative charge of Oxygen ion, the electrostatic force of attraction is produced between them.
This electrostatic force between Magnesium ion and Oxygen ion results in an ionic bond between them.
Hence, MgO is an ionic compound.
I hope you have understood the reason why MgO is an ionic compound.
Check out other compounds to see whether they are ionic or covalent;
Is CCl4 (Carbon tetrachloride) Ionic or Covalent?
Is CaO Ionic or Covalent?
Is KCl (Potassium chloride) Ionic or Covalent?
Is O2 Ionic or Covalent?
Is H2S Ionic or Covalent?
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.
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