Covalent bonding

07/04/16

“What happens when atoms share electrons?”

Atoms often have free space for electrons in their valence shell, which makes them unstable and prone to reaction. However, is it possible for atoms to share their electrons in order to fill the void? Let’s look at an example. Oxygen has only six of its eight valence electrons occupied, while hydrogen has one out of two. This means that oxygen needs to find a way to retrieve two electrons and the hydrogen needs to find a way to receive one electron. This can be accomplished if two hydrogen atoms shared their electrons with the oxygen atom. Then the oxygen would have it’s valence shell filled and the hydrogen would also. This will for a chemical bond known as a covalent bond. Covalent bonds are completely made up of non-metals, and they are extremely strong and durable, making it very difficult to dissolve a covalent bond.

Numerical electron configuration

07/03/16

“How can we quantify electron configuration?”

When dealing with electron configuration, wouldn’t be usefull if we could somehow create a framework to conceptualize everything? As discussed earlier, the electrons of an atom are organized into shells and orbitals, the former dealing with the distance from the center of the nucleus, and the latter dealing within the probabilistic location To start off, we will assign a number to each of the atomic shells, with the first shell being called the “first shell”, the second the “second shell”, and so on. Furthermore, each of these shells will be divided into subshells. Subshells are the set of atomic orbitals that are most similar to each other. The first shell will have one subshell (called the 1s subshell), the second shell will have two (the 2s and 2p respectively), the third will have three (3s, 3p, and 3d), and so on. Each of the letters indicate a different orbital of the subshell. Each orbital can hold two electrons, and each subshell will be able to hold 4L+2 electrons, with L being the orbital value of the subshell (for example, the s subshell will have an orbital value of 0,the p a 1, and so on).

Now, how do we incorporate the change in electrons into this system? When electrons flow into an atom, they will enter the orbital with the lowest level of energy associated with it, as that is the easiest one to deal with. The two factors that affect the energy level are the shell and orbital value. As a result, it is possible to have an shell with a higher value but a lower orbital be filled before  one with a lower value shell but higher orbital. For example, the 4s orbital will be filled before the 3d one since the 3d has a higher energy level. The pattern for this phenomena can be seen on the picture for this article.

Finally,  this brings us to the outermost shell of the atom. If this shell, termed the valence shell by chemists, has a lack of filled space, then it will be able to react with other chemicals to create chemical reactions and make chemical bonds.

Intro to electron configuration

07/02/16

“How can we find out how much free space an atoms has for electrons?”

All atoms have the potential to have electrons. However, how can we find out how many electrons an atoms has and how much it can hold? To solve this question, let’s start off with one fact. All electrons revolve around the nucleus. Because there is a mutual interaction between the two particles, there will be a certain level of energy associated with the two particles that binds them together. Furthermore, as a consequence of the laws of quantum mechanics, all energy levels are in discrete forms.  When the electron receives enough energy to surpass the binding energy, they will jump to the next possible level. The energy required to surpass the binding force is called the ionization energy and the different levels are called valence shells. As a result of the Heisenberg uncertainty principle, these electrons will have different possibilities of location within these valence shells, and that probability depends on the amount of electrons inside. These probabilistic locations are called orbitals. Chemists have termed these series of classifications to be the electron configuration of the system.