To determine the electron configuration of lithium, we should consider its atomic number and the arrangement of electrons in different energy levels.
1. Identify the atomic number of lithium: Lithium has an atomic number of 3. This means it has 3 electrons.
2. Distribute the electrons into different energy levels:
- The first energy level (shell) can hold up to 2 electrons.
- Hence, we place the first 2 electrons in the 1s orbital: \(1s^2\).
- The second energy level can hold up to 8 electrons, but since we only have 1 electron left, it goes into the 2s orbital: \(2s^1\).
Putting it all together, the electron configuration of lithium is:
[tex]\[ 1s^2 2s^1 \][/tex]
So, the correct answer is [tex]\( 1s^2 2s^1 \)[/tex].
