Electronic Configuration of 118 Elements
- Hydrogen: 1s1
- Helium: 1s2
- Lithium: 1s2 2s1
- Beryllium: 1s2 2s2
- Boron: 1s2 2s2 2p1
- Carbon: 1s2 2s2 2p2
- Nitrogen: 1s2 2s2 2p3
- Oxygen: 1s2 2s2 2p4
- Fluorine: 1s2 2s2 2p5
- Neon: 1s2 2s2 2p6

Exceptions in Electronic Configuration
- Chromium: 1s2 2s2 2p6 3s2 3p6 4s1 3d5 (Exception: 4s1 instead of 3d4)
- Copper: 1s2 2s2 2p6 3s2 3p6 4s1 3d10 (Exception: 4s1 instead of 3d9)
- Silver: 1s2 2s2 2p6 3s2 3p6 4s1 3d10 (Exception: 4s1 instead of 4d9)
- Gold: 1s2 2s2 2p6 3s2 3p6 4s1 3d10 (Exception: 4s1 instead of 4d10)

Explanation
The electronic configuration of an element specifies the distribution of electrons in its atomic orbitals. The exceptions in electronic configurations occur due to the stability gained by having a half-filled or fully filled subshell.
In the case of Chromium, it has a configuration of [Ar] 3d5 4s1 instead of [Ar] 3d4 4s2 because having a half-filled d orbital (3d5) is more stable than a partially filled d and s orbital. Similarly, Copper, Silver, and Gold follow the same trend to achieve stability by having a fully filled or half-filled d orbital.
These exceptions are important to understand as they illustrate the principles of electron configuration and the concept of stability in atoms.