Valence Electrons in Arsenic (As)
Calculate the number of valence electrons in Arsenic using its electron configuration step by step.
Valence Electrons in Arsenic
Determine the number of valence electrons in Arsenic (As, Element 33)
Step 1: Look up the electronic configuration for Arsenic
The abbreviated (condensed) ground electronic configuration for Arsenic is:
[Ar] 3d10 4s2 4p3
Calculate Electronic Configuration for Arsenic
Step 2: Identify the outermost electrons using the electronic configuration
Electrons in atomic orbitals outside the [Ar] core are the outermost electrons:
3d10 4s2 4p3
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 |
|---|---|---|---|
| 3d10 | 3 | d | 10 |
| 4s2 | 4 | s | 2 |
| 4p3 | 4 | p | 3 |
The outermost electrons with the largest principal quantum number (in this case, n = 4) are valence electrons.
Answer
Arsenic (As) has 5 (2 + 3) valence electrons.
