The chemical unions have to do with the electronic cloud, but without touching the nucleus, since in case of touching it we would be talking about nuclear physics or what is the same of rupture of the nuclei. In this case, we would be talking about the union of atoms through electrons. The way to combine will depend on the structure of the atoms, if they have more positive charges or more negative charges. Remember that electrons revolve around the nucleus, forming a kind of rings also known as energy levels or shells.
Precisely, in the outermost layer of the atom, electrons overlap or share, giving rise to chemical bonds that can be ionic or covalent.
In a simple way, when an atom loses an electron an ionic bond is being produced. On the other hand, if an electron is shared by two atoms, a covalent bond is being produced. It should be noted that if the electron is shared by two atoms at the same time, it is said to be a non-polar bond, but if one of the atoms maintains that shared electron for longer than the other, we would be talking about a polar bond.
But in case it was not clear to you, we are going to see in more detail how to differentiate an ionic bond from a covalent bond.
What do you need to differentiate an ionic bond from a covalent bond?
- Pencil or pen and paper to be able to follow the examples that are cited.
- Periodic table of elements.
Instructions to differentiate an ionic bond from a covalent bond
- If you have to explain to a child the difference between the two links, this explanation may help you:
- Imagine that it is a family that lives together, a father, a mother and a child.
- If they all live together in the same house, a nonpolar covalent bond is taking place. Both parents share the child at the same time.
- But if the mother and father separate, it is normal for the mother to spend more time with the child and the parents alternate on weekends to share the child. Here a polar covalent bond is taking place, since the mother has more time with the child.
- In the event that the mother goes to live abroad, the father will no longer be able to see the child. Therefore, an ionic bond has occurred. Because the child can no longer be with the father.
- Next we are going to focus more on the characteristics to know what is a covalent bond and what is an ionic bond.
- Ionic bonds
- They occur between metals and non-metals.
- There is a transfer of electrons from metals to non-metals.
- Opposite ions form and attract each other.
- Electrons are gained or lost.
- Example: If we put together a molecule of Sodium (Na) with a molecule of Chlorine (CL), we know that Na, because it is placed in the first column of the periodic table, has 1 electron in the last level and Cl 7 electrons. When the transfer occurs, sodium, being a metal, transfers an electron to chlorine. So Chlorine gains an electron and Sodium loses it. Now when this transfer of electrons occurs, the Na has been left with more positive charges and the Cl will have a negative charge when it gains an electron. Being of opposite charges they attract each other, coming together in the NaCl molecule.
- Covalent bond
- It occurs at the junction of two nonmetals.
- They do not give electrons, but share them.
- By sharing they complete their levels.
- Example: If we put two oxygen molecules together, they both have 6 electrons in the last level. What they do is share because they are not metals. If we tried to make an ionic bond, we would have a stable oxygen with 8 electrons, but the other would keep half. Since one is stable and the other is not, we could not put them together. So you have to look for another way, which is by sharing electrons, that is, we would be talking about a covalent bond. The sharing of electrons implies that each hydrogen puts a number of electrons through the middle zone that first go around one atom and then the other. Therefore, if they each share one electron each will have seven electrons. However, with 7 electrons they are still not stable and must share one more electron to reach 8 and be stable. This is that each oxygen has shared two electrons each. So these two oxygen molecules come together in a chemical element that is O2, two oxygen atoms joined by a covalent bond.
- Unlike ionic bonds, covalent bonds can be classified by:
- Its polarity: polar and non-polar.
- By the way they share electrons: simple, double, triple or dative.
Tips to differentiate an ionic bond from a covalent bond
- The dative covalent bond is also known as coordinate or triple. In this type of bond, one of the two atoms contributes all the electrons. While the pure covalent bond shares the same number of electrons.
- Regarding polarity, as we explained at the beginning of this article, it will depend on the electronegativity of the atoms, that is, on the attraction capacity of the other element. If there is no difference, it will be non-polar, like the bond between Chlorine and Chlorine. It will also occur in Chlorine, Hydrogen, Oxygen, Nitrogen, Fluorine, Bromine or Iodine. As long as they link to each other.