The periodic table is a catalog of all the atoms that exist on our planet. The elements are organized in increasing atomic numbers and there is a recurring pattern called the ‘periodic law’ in their properties.
Hydrogen (H) is the first element, is located on the top left of the periodic table, its atomic number is 1; the biggest atom, Oganesson, on the bottom right, has 118 protons and electrons. To accommodate the electrons, the atom uses seven levels of energy, which are represented by the rows in the periodic table.
In the first level, atoms accommodate a maximum of 2 electrons, but increases when the level is higher. The atomic representation will be as follows.
Surrounding the nucleus is the first shell or level of energy, there the atoms can allocate until 2 electrons, hydrogen and helium are at this level.
The second and third levels are bigger and allow until 10 electrons in each one.
The fourth and fifth shells can accommodate until 18 electrons, here is when the elements in the middle of the table appear.
Finally, the sixth and seventh shells allow 32 electrons, and the last two rows of the elements in the table are accommodated.
Atoms use these layers to transfer their electron from their ground state to a higher layer when they receive external energy. This new energy level can be the closest or one that is in a higher place, depending on the energy value received, but it must be a value that the atom recognizes.
Electrons do not remain in an excited state for long, they emit energy in a luminous form unique to that atom.
For example, copper atoms will emit blue light, lithium atoms emit red light and barium atoms emit green radiation.
The release of energy allows them to return to their basic energy level.