Valence Electrons in Lanthanum (La)
Calculate the number of valence electrons in Lanthanum using its electron configuration step by step.
Valence Electrons in Lanthanum
Determine the number of valence electrons in Lanthanum (La, Element 57)
Step 1: Look up the electronic configuration for Lanthanum
The abbreviated (condensed) ground electronic configuration for Lanthanum is:
[Xe] 5d1 6s2
Calculate Electronic Configuration for Lanthanum
Step 2: Identify the outermost electrons using the electronic configuration
Electrons in atomic orbitals outside the [Xe] core are the outermost electrons:
5d1 6s2
Step 3: Use the principle quantum number to identify the valence electrons
Extract the principle quantum number, n, and number of electrons from the electron configuration:
| Electron Configuration | n | Orbital | Number of Electrons |
|---|---|---|---|
| 5d1 | 5 | d | 1 |
| 6s2 | 6 | s | 2 |
The outermost electrons with the largest principal quantum number (in this case, n = 6) are valence electrons.
Answer
Lanthanum (La) has 2 valence electron(s).
