energy sublevels in an atom they represent the form in which electrons are organized in electron shells, their distribution in a molecule or atom. These energy sublevels are called orbitals.
The organization of electrons into sublevels is what allows chemical combinations of different atoms and also determines their position in the Periodic Table of Elements.
Electrons are arranged in the electron shells of an atom in a specific way using a combination of quantum states. When one of these states is occupied by an electron, the remaining electrons must be transferred to another state.
introduction
Each chemical element in the periodic table is made up of atoms, which in turn are made up of neutrons, protons, and electrons. Electrons are negatively charged particles that are found around the nucleus of any atom, distributed into electron orbitals.
Electron orbitals are the volume of space in which an electron is 95% likely to be found. There are different types of orbitals with different shapes. Each orbital can hold a maximum of two electrons. The first orbit of an atom is where the electrons are most likely to be found.
Orbitals are labeled s, p, d, and f, which stands for Sharp, Principle, Diffuse, and Fundamental, and are combined when atoms join together to form a larger molecule. These combinations of orbitals are found in each layer of the atom.
For example, in layer 1 of the atom there are S orbitals, in layer 2 there are S and P orbitals, within layer 3 of the atom there are S, P and D orbitals and finally in layer 4 of the atom there are all S, P, D and F orbitals.
Also in the orbitals we find different sublevels, which in turn can store more electrons. Orbitals at different energy levels are similar to each other, but occupy different areas in space.
The first orbit and the second orbit have the same characteristics as the S orbit, having radial nodes, have a higher probability of spherical volume, and can only contain two electrons. However, they are located at different energy levels and therefore occupy different places around the nucleus.
Location in the periodic table of elements
Each element’s electron configuration is unique, so they determine their position in the Periodic Table of Elements. This position is determined by each element’s period, and its atomic number is the number of electrons that an atom of the element has.
Thus, using the periodic table to determine the electron configuration of atoms is key. Elements are divided into groups according to their electron configurations as follows:
Each orbital is represented in specific blocks of the Periodic Table of Elements. For example, the S orbital block is the alkali metal region, the first group in the table and where six elements are found: lithium (Li), rubidium (Rb), potassium (K), sodium (Na), francium (Fr), and cesium (Cs), as well as hydrogen (H), which is not a metal but a gas.
This group of elements has an electron that is usually easily lost, forming a positively charged ion. They are the most active metals and the most reactive.
Hydrogen is a gas in this case, but it is in Group 1 of the Periodic Table of Elements because it also has only one electron. Hydrogen can form ions with a single positive charge, but it takes much more energy to reach its single electron than it does to remove electrons from the other alkali metals. When hydrogen forms compounds, it usually forms covalent bonds.
However, at very high pressures, hydrogen becomes metallic and behaves like the other elements of its group. This happens, for example, inside the core of the planet Jupiter.
Group 2 corresponds to the alkaline earth metals, as their oxides have alkaline properties. Among the elements of this group we find magnesium (Mg) and calcium (Ca). Their orbitals also belong to the S level.
Transition metals, which correspond to groups 3 through 12 in the periodic table, have D-type orbitals.
The elements of the table belonging to groups 13-18 correspond to P. orbitals, and finally the elements known as the lanthanides and actinides have orbitals named F.
The location of the electron in the orbital
Electrons are in the orbitals of an atom as a way to reduce energy. So if you want to increase energy, the electrons will fill the main orbital levels, moving away from the nucleus of the atom.
We must take into account that electrons have a property known as spin. This is a quantum concept that determines, among other things, the spin of an electron within an orbital. Which is important for determining your position on the energy sublevels.
The rules that determine the position of electrons in the orbitals of an atom are as follows:
- Aufbau principle: Electrons fall into lower energy orbitals first. This principle is based on the energy level diagrams of certain atoms.
- Pauli exclusion principle. An atomic orbital can describe at least two electrons. This means that only two electrons with different electron spins can occupy an atomic orbit.
This means that the atomic orbital is an energy state.
- Hund’s rule: When electrons occupy orbitals with the same energy, electrons will fall into empty orbitals first. This means that electrons prefer parallel spins in individual orbitals of energy sublevels.
Electrons will fill all orbitals in the sublevels before they collide with opposite spins.
Special electronic configurations
There are also atoms with special cases of energy sublevels. When two electrons occupy the same orbit, not only must they have different spins (as specified by the Pauli exclusion principle), but the electron binding increases the energy slightly.
In the case of energy sublevels, half full and one fully full sublevel decrease the energy of the atom. This makes the atom more stable.
links
- Electron configuration. Retrieved from Wikipedia.com.
- Electron Configurations Intro. Retrieved from chem.libretexts.org.
- Orbitals and Bonds. Retrieved from chem.fsu.edu.
- Periodic table, main elements of the group. Retrieved from newworldencyclopedia.org.
- Principles of electrical equipment configuration. Recovered from sartep.com.
- Electron configuration of the elements. Retrieved from science.uwaterloo.ca.
- Electron Spin. Retrieved from hyperphysics.phy-astr.gsu.edu.