Total Electrons in Chromium with (n+l) = 4
In determining the total number of electrons present in chromium when (n+l) = 4, we need to understand the electron configuration of chromium (Cr).
1. Understanding Chromium's Electron Configuration
- Chromium has an atomic number of 24, meaning it has 24 electrons.
- The electron configuration of chromium is:
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
This configuration reflects the actual distribution of electrons in various atomic orbitals.
2. Calculating (n+l) Values
- The (n+l) rule helps determine the energy levels of electrons in an atom. Here, n is the principal quantum number, and l is the azimuthal quantum number.
- For different orbitals:
- s orbital (l = 0): n + l = 1 (for 1s), 2 (for 2s), 3 (for 3s), 4 (for 4s)
- p orbital (l = 1): n + l = 2 (for 2p), 3 (for 3p)
- d orbital (l = 2): n + l = 3 (for 3d)
- The only orbitals that satisfy (n+l) = 4 are:
- 4s (n=4, l=0): 2 electrons
- 3d (n=3, l=2): 5 electrons
3. Total Electrons for (n+l) = 4
- Therefore, when (n+l) = 4, the total number of electrons in the relevant orbitals is:
- 4s: 2 electrons
- 3d: 5 electrons
- Total = 2 + 5 = 7 electrons
Conclusion
In conclusion, for chromium, the total number of electrons present when (n+l) = 4 is 7 electrons.