Below all the others on the diagram is the energy level of the ground state of the atom, the energy levels of the excited states are located above the ground level at distances proportional to the difference between the energies of the excited and ground states. Transitions of an atom from one state to another are depicted by vertical lines between the corresponding levels on the energy diagram, the direction of the transition is indicated by an arrow.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.