Tag Archives: bond


We are going to use the Periodic Table to talk about a very important element, which is Carbon, one of the stars of modern chemistry because is present in almost every compound  around us. Carbon itself is the principal protagonist of the part of Chemistry called Organic Chemistry.


Carbon is located in Group 4A of the Periodic Table of the Elements, that means this Element will be forming compounds sharing until 4 electrons.

Carbon and Organic Chemistry are present in different kind of materials for example in paints, rubbers, oils (and all petrochemical derivates), plastics (polymers of carbon), and even in Steel forming alloys with  metals.

In live organisms Carbon is part of the skin, hair, blood (as amino acids and proteins), fats (or lipids), carbohydrates such us glucose, DNA, RNA, vitamins, and carbon dioxide, that is why is important for Pharmaceutical  and Food industries.

Carbon is also present in graphites (as in pencils) and diamonds.

Organic Chemistry is based in an element called Carbon.

How Carbon is present in all different compounds?

There are two principal characteristic of this Element, that make him different and special from other Elements:

1st) When form compounds, they share electrons, that means that they don’t take or give electrons (they do not create ionic bonding). They form covalent bondings

2nd) They are able to share until 4 electrons. Most Elements win or take less than 3 electrons.

Now, we’ll try to see How Carbon creates compounds

We know that Carbon has 4 electrons in its valence shell, these electrons are in orbitals, one electron in one orbital.

The orbitals are around Carbon, not forming 90º or 180º  among them, but 109.5º in all cases.

To complete each orbital we need 1 electron, that can be provided for an Hydrogen for example. If that is the case, one Carbon will need 4 Hydrogens, and the final molecule is Methane, CH4.

A better representation of, methane, is this. One Carbon surrounded by 4 Hydrogens at the same distance and same angle among them.

When Carbon wants to create a bigger molecule, it replaces one Hydrogen for another Carbon and complete the other bondings with other atoms, as Hydrogens or another Carbon.

For example, when in a molecule we have 3 Carbons, then we will need 8 Hydrogens, and in that case the molecule is called Propane.


In a Non polar Covalent Bond, atoms share their electrons equally. That happens when, they have the same electronegativity or the same electron affinity. The best examples for this  kind of bonds are molecules created through the union of atoms of the same element, as in H2, N2, O2, Cl2  

When non-polar molecules interact among them, there are negligible forces of attraction, and they remain as individual molecules, that means these substances are gases.

In our environment we have these substances in the Air, which has approximately the following composition, 78% of N2, 21% of O2, 0.9% Ar (noble gas)




Covalent bonds involve the sharing of electrons by two atoms, in contrast to the transfer of electrons in Ionic Bonds.

Covalent Bond is another way to create a noble gas configuration for each atom. For example, Hydrogen has 1 electron, and needs another to have the same electronic configuration as gas noble Helium. Chloride, has 7 electrons, and with one more acquire the distribution of Argon.
However, when H-Cl bond is formed, there is still an unequal sharing of the electrons, because the electrons spend more time around the more nonmetallic atom, and more electronegative, in this case the Chloride, giving us a Polar Covalent Bond.
In a Polar Covalent Bond there is an atom being slightly more positive (H) than the other (Cl), i.e., the bond will produce a dipole moment, which can be evident when many H-Cl molecules interact among them, because the positive extreme of one molecule will be attracted by the negative part of the other. producing, in most of the cases, liquid substances. The most popular compound with Polar Covalent Bond is Water, where the Oxygen is the slightly negative extreme of the molecule.



Atoms in our planet are not by themselves, they are joined at least to another atom through a chemical bond. Bonds allow atoms achieve a stable electron configuration, similar as the noble gases, which are mostly not joined to other atoms.

The more important kind of bonds are Ionic and Covalent.

Ionic Bond

Is formed between atoms from the groups IA, IIA (metals) and VIA, VIIA (non metals). In this bond,  metals donate one or more electrons to the non-metals leading to form ions, one of them positively charged (cation) and the other with negative charge (anion).

For example, common table salt is Sodium Chloride. When Sodium (Na) and Chlorine (Cl) are combined, the sodium atoms lose an electron, forming cations (Na+), and the chlorine atoms gain an electron to form anions (Cl).

Na + Cl =  Na+ + Cl = NaCl 

Most of the Ionic compounds in our planet are in the solid state and form lattice structures. The two principal factors in determining the form of the lattice are the charge of the ions and their sizes.