Valence Electrons in Chlorine (Cl)
Calculate the number of valence electrons in Chlorine using its electron configuration step by step.
Valence Electrons in Chlorine
Determine the number of valence electrons in Chlorine (Cl, Element 17)
Step 1: Look up the electronic configuration for Chlorine
The abbreviated (condensed) ground electronic configuration for Chlorine is:
[Ne] 3s2 3p5
Calculate Electronic Configuration for Chlorine
Step 2: Identify the outermost electrons using the electronic configuration
Electrons in atomic orbitals outside the [Ne] core are the outermost electrons:
3s2 3p5
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 |
|---|---|---|---|
| 3s2 | 3 | s | 2 |
| 3p5 | 3 | p | 5 |
The outermost electrons with the largest principal quantum number (in this case, n = 3) are valence electrons.
Answer
Chlorine (Cl) has 7 (2 + 5) valence electrons.
