In atoms, electrons don’t just stay stationary relative to the nucleus, or orbit the nucleus in a fixed path. Instead they are found as, well, they are not found. It is impossible to know the exact location of an atom. But, there are areas which there is a probability of finding an electron, called electron probability clouds. The configuration of these clouds and electrons are called orbitals, a.k.a atomic orbitals.
Orbitals have 4 types; S, P, D and F orbitals. There are multiple orbitals for every shell, for example the first shell only has the 1s orbital, while the second shell has the 2s and the 2p orbitals.
All orbital types except S can be separated into various counterparts. A p-type orbital has 3 parts; px, py and pz. The d and f orbitals are more complicated, and I won’t go over them in this post.
Orbitals, take part in most phenomena that most people don’t know the reason to. A good example of this is why the water molecule is bent. This happens because of orbitals trying to not overlap each other (because two electrons repel each other). And because they get as far away as possible from each other, oxygen takes a tetrahedral shape. And if oxygen is tetrahedral, no two bonds will make the molecule straight. A similar example is why methane is tetrahedral. Carbon is tetrahedral too, just like oxygen. A tetrahedron has four vertices, methane has four hydrogen atoms. So, the four hydrogen atoms bond to each of the vertices of the tetrahedron the carbon forms, therefore making methane tetrahedral.
This is all for now, I am in a rush right now, and that is why I couldn’t write too much. This is all for this post, I will make another post on Sunday explaining orbitals, more in detail. Take care!
When you look at some molecules you might say “Those atoms are not connected, how are they molecules?”. Because of ionic bonding. In ionic bonding, the atoms are not connected by a pair of electrons like in covalent bonding, they are connected by magnetic forces. One of the atoms are negatively charged, the other is positively charged. It doesn’t have to be single atoms too, they can be two different charged structures as well.
Continue reading “Ionic bonding in molecules”
Covalent bonds are like two encyclopedias sharing information. They both need a piece of information, so they give each other information. Those pieces of information are in both encyclopedias. To get a covalent bond, replace encyclopedias with atoms, and replace pieces of information with electrons.
For a simple example, lets take H2. A hydrogen atom has one valence electron, and for the shell to be filled, it needs one more electron because the first shell (also called the K shell) needs 2 electrons to be filled. How convenient! If the amount of valence electrons is equal to the amount of electrons needed to fill the shell, we can just make a diatomic molecule. You can visualise two hydrogen nuclei with two electrons in between
In the hydrogen molecule, an electron is with both of the atoms. Just like the encyclopedias, the pieces of information are in both encyclopedias.
Lets give another example: the methane molecule (CH4). This works as so: The four hydrogens are arranged tetrahedrally around the carbon atom, and they all share electrons with the carbon. You can visualise a carbon nucleus with four hydrogen nuclei surrounding the carbon in a tetrahedron, and pairs of electrons between the hydrogens and carbon.
But there is an important rule for covalent bonds to be formed.Both atoms have to be nonmetals! If any of them are metals, they wont form a covalent bond. The reason for this is that metals want to give electrons away, but nonmetals want to take electrons. If one of them was a metal, they would make an ionic bond, which I will write about in my next post.
Now, try to understand the molecule ammonia (NH3). As an extra, try to understand why the shape isn’t completely flat, but a little curved.