Energy Level Diagram

In chemistry, an electron shell, also known as an energy level, can be thought of as an orbit around the nucleus of an atom in which electrons are present.The “K shell” is the shell that is closest to the nucleus, followed by the “L shell,” then the “M shell,” and so on as the shells move away from the nucleus. In addition to letters (K, L, M,…) and quantum numbers (n = 1, 2, 3, 4, and so on), the shells can be represented by symbols such as alphabets.

Each shell contains a fixed number of electrons – in this case, two electrons per shell.

For example, the first shell, known as the “K shell,” contains two electrons. The second shell, known as the “L shell,” contains eight electrons. The third shell, known as the “M shell,” contains 18 electrons.

In order to determine the number of electrons that can be held in each shell, the general formula is as follows: 2(n2). It is thought that electrons are drawn to the nucleus of the atom, where they take up residence in its outer shells because the inner shells have already been completely taken up by the rest of the electrons.

Understanding the energy level diagram: 

Using the Grotrian diagram, we can see that light emission and absorption occur at the same wavelengths, which is useful in understanding how photosynthesis works. Walter Grotrian, a German astronomer who lived in the twentieth century, is the inspiration for this concept.

It moves from one energy state to another when a molecule or an atom absorbs light or collides with another atom or ion that provides sufficient electrical or magnetic energy.

In most cases, the emission is initiated by an atom that has been excited to its upper state either by collision with another atom or by absorption of light from the surrounding environment.

Hydrogen atom transitions and series:

Let’s take a look at the hydrogen atom from the standpoint of the Bohr model of physics. Assume that a beam of white light (which is composed of photons of all visible wavelengths) is shining through a gas of atomic hydrogen at room temperature. Using a photon with a wavelength of 656 nanometers, you can raise an electron in a hydrogen atom from the second to the third orbit, which is exactly what you need to do. Photons with this particular wavelength can be absorbed by those hydrogen atoms whose electrons are in a second level of orbit as all of the photons of different energies (or wavelengths or colours) stream by the hydrogen atoms. The photons of this wavelength and energy will be absent from the general stream of white light when they are absorbed, as the electrons on the second level move up to the third level as a result of their absorption.

The energies of other photons will be sufficient to raise electrons from the second to the fourth orbit, or from the first to the fifth orbit, and so on. Only photons with these specific energies have the ability to be absorbed. All of the other photons will pass right through the atoms unaffected by the atoms. As a result, only certain wavelengths of light are absorbed by hydrogen atoms, resulting in dark lines appearing in the visible spectrum at those wavelengths.

Example of energy level diagram:

Take, for example, the elements fluorine and lithium, which are depicted in the illustration below. Fluorine has seven electrons in its outermost energy level, which is energy level II, out of a total of eight possible electrons. A single additional electron would increase the stability of the system because it would fill the outermost energy level. Lithium, on the other hand, only has one electron in its outermost energy level, out of a total of eight possible electrons (also energy level II). A single less electron would make it more stable because it would have a full outer energy level, which would make it more stable (now energy level I).

Because of the large number of valence electrons present in both fluorine and lithium, both elements are extremely reactive. Fluorine will readily gain one electron, and lithium will equally readily give up one electron in order to become more stable, both of which are beneficial. In fact, the elements lithium and fluorine will react together, as illustrated in the illustration below. When the two elements react, lithium transfers one of its “extra” electrons to fluorine, resulting in a net transfer of one electron.

Conclusion:

It is necessary to use an energy level diagram to represent the various energy states available in each atom.In chemistry, an electron shell, also known as an energy level, can be thought of as an orbit around the nucleus of an atom in which electrons are present.Molecular transitions in the vibrational or rotational energy levels of a molecule can also take place. Energy level transitions can also be nonradiative, which means that no photons are emitted or absorbed as a result of the transition.