To find the ground state electron configuration of an atom, you need to follow a specific order of filling the atomic orbitals with electrons, known as the Aufbau principle. Here's a step-by-step guide:
Determine the atomic number of the element you are working with. This number corresponds to the number of electrons in the atom.
Begin filling the orbitals with electrons starting from the lowest energy level (closest to the nucleus) and moving to higher energy levels. The order of filling follows the Aufbau principle, which is based on the increasing energy levels of the orbitals.
The order of filling orbitals is as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, and so on.
For each orbital, the maximum number of electrons it can hold is given by the following formulas:
- s orbital: 2 electrons
- p orbital: 6 electrons
- d orbital: 10 electrons
- f orbital: 14 electrons
Fill the orbitals in the order mentioned above, placing the appropriate number of electrons in each orbital until you have accounted for all the electrons in the atom.
For example, let's take the element carbon (C) with atomic number 6:
- The 1s orbital can hold up to 2 electrons. Fill it with 2 electrons.
- The 2s orbital can hold up to 2 electrons. Fill it with 2 electrons.
- The 2p orbital can hold up to 6 electrons. Fill it with 2 electrons, leaving 4 electrons.
- Distribute the remaining 4 electrons in the 2p orbitals (one electron per orbital).
- The resulting ground state electron configuration for carbon is 1s² 2s² 2p².
Following this procedure, you can determine the ground state electron configuration for any atom based on its atomic number and the Aufbau principle.