The Allegory of the Cave. The dialogue between Socrates and Glaucon is probably fictitious and composed by Plato; whether or not the allegory originated with Socrates, or if Plato is using his mentor as a stand-in for his own idea, is unclear. In the dialogue, Socrates asks Glaucon to imagine a cave, in which prisoners are kept.
The d sublevel consists of five orbitals that can hold a maximum of  two electrons each. The total maximum number of electrons that the  d sublevel can hold is 10 electrons.
Electrons orbit the nucleus in energy levels, which are also called shells. These energy levels contain sub-shells, or orbitals, each of which holds a certain number of electrons. By looking at the electron configuration for titanium, it is possible to determine how its electrons are arranged. There are two electrons in the s orbital of the first energy level. The second level contains eight electrons, with two in the s orbital and six in the p orbital.