Chapter 11: Introduction to Modern Atomic Theory

Where is the single electron in the hydrogen atom, what level, what sublevel and what orbital is the elctron located?

The electron is in the orbital of the lowest energy. Which orbital is that?...1s.

What level is the 1s orbital located? What sublevel is the 1s orbital located? It is the first level (n = 1). The first level has only one sublevel, the s sublevel.

We write something called the electron configuration to communicate the location of the electron in the hydrogen atom (or any atom).

For hydrogen, with its one electron the electron configuration is 1s¹.

The orbital diagram for hydrogen is;

An orbital can hold two electrons, independent of whether it is an s orbital, a p orbital, a d orbital or an f orbital. We use the concept of spin to differentiate the difference between the two electrons in an orbital. One electron has spin in the 'up' direction as shown above, the next electron will have the spin in the 'down' direction.

The orbital diagram and the electron configuration provide different information. The electron configuration tells us how many electrons are in a particular shell and subshell. The orbital digram tells us the same thing as the electron configuration, plue it tells us the occupancy of each orbital in the atom...how many electrons and their spin.

When placing electrons into an orbital it is arbitrary which spin the first electron has, 'up' or 'down'. However, the spin of the second electron must be opposite of the first.

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