Chapter 11: Introduction to Modern Atomic Theory

An energy level diagram for the Bohr model of the hydrogen atom is shown on the left. The ground state, lowest energy level, is n = 1. As n increases the energy of the level gets higher. As n increases the energy levels get closer together.

In the Quantum Mechanical model of the hydrogen atom we view the electron as having wave properties. This introduces some complexity to the energy level diagram. Closer study of the emission spectrum of the hydrogen atom also reveals fine-lines suggesting the energy level diagram for the hydrogen atom is more complex.

For example,

the first level ( n = 1) has one sublevel;
the second level contains two sublevels;
the third level contains three sublevels;
the fourth level contains four sublevel; etc.

It also turns out that each of these sublevels contain orbitals (the three dimensional region of space where the probability of finding the electron is high).

the first level ( n = 1) has one sublevel and one orbital;
the second level contains two sublevels which contain four orbitals;
the third level contains three sublevels which contain nine orbitals;
the fourth level contains four sublevel which contains sixteen orbitals.

So when an electron is located in the ground state it is located in the only sublevel in that level and it occupies the only orbital in that sublevel.

What do these sublevels and orbitals look like? If there are thirty orbitals in the first four levels how do we keep track of them? How are they labeled?

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