1. Electron Configurations
More on the Electron
Electron Configurations

2. Orbit(al)s of Electrons
You know that electrons are found in orbits that surround the nucleus of the atom.
A new idea for you is that there are 4 different types of orbitals that are possible, we call each type of orbital a different letter, s, p, d, or f.
In addition to these letter differences, each has a different shape. s for example, is a spherical shape, while p is a dumb bell shape.

3. Orbitals and Electron Box Diagrams
For each orbital, the maximum number or electrons is 2.
So, we use a special designation to assign and fill orbitals in elements:
For hydrogen (having only 1 electron) – 1s1
As we move along the elements, increasing the number of electrons, we move into additional orbitals, then we move up into the next quantum number (i.e. Orbit in Bohr model)
For helium – 1s2 (we only show the same orbital once)

4. Orbitals (cont’d)
Once we have filled the s orbital (only 2 electrons, and only 1 s orbital), we move to the next quantum number and start again at the s orbital.
For lithium – 1s22s1
When we have to enter the p orbitals, we can have up to 3 p orbitals, so we can go up to 6 electrons.
For oxygen – 1s22s22p4

5. Try writing electron configurations
Write the electron configurations for the first 10 elements