To determine the electron configuration for lithium, we need to know its atomic number, which is 3. This means lithium has 3 electrons.
The distribution of electrons in atomic orbitals follows the Aufbau principle, which states that electrons fill orbitals starting from the lowest energy level to the highest. The order of filling is in accordance with the increasing energy levels of the orbitals.
Here is the process:
1. First Electron (1s orbital):
- The first electron will occupy the lowest energy orbital, which is \(1s\).
- Filling the \(1s\) orbital requires 2 electrons, but since we only need to place one electron in this step, we write: \(1s^1\).
2. Second Electron (1s orbital):
- The second electron will also occupy the \(1s\) orbital (as it can hold a maximum of 2 electrons).
- We now have: \(1s^2\).
3. Third Electron (2s orbital):
- The next electron will occupy the next available lowest energy orbital, which is the \(2s\) orbital.
- In this configuration, we add 1 electron to the \(2s\) orbital: \(2s^1\).
Combining these, the electron configuration for lithium is:
[tex]\[1s^2 2s^1\][/tex]
Therefore, the correct electron configuration for lithium given in the options is:
[tex]\[1s^2 2s^1\][/tex]
