Beryllium has atomic number 4, so 4 protons. The electronic configuration 1s2 2s2 has 2 electrons in the 1s shell and 2 electrons in the 2s shell, which is 4 electrons.
1s2 2s2 2p3 or otherwise denoted [He]2s2 2p3
[He] 2s2 2p4
The full configuration of He 2s2 2p6 is 1s2 2s2 2p6. This configuration represents a neutral oxygen atom with its electrons distributed in the 1s, 2s, and 2p orbitals.
The electron configuration of beryllium is written as [He] 2s2. This means that it has 2s2 electrons above the configuration of Helium.
2s2-s-15 = (2s+5)(s-3)
The investigator will find that 1s2 2s2 2p6 is the electron configuration for neon.
The abbreviated electron configuration of oxygen is [He] 2s^2 2p^4.
Sodium 2, 8, 1Magnesium: 2, 8, 2Aluminium: 2, 8, 3Silicon: 2, 8, 4Phosphorus: 2, 8, 5Sulphur: 2, 8, 6Chlorine: 2, 8, 7Argon: 2, 8, 8
The element with a valence electron configuration of 2s2 is beryllium. Beryllium has 4 electrons, with 2 in the 2s subshell, which makes it have a valence electron configuration of 2s2.
[He] 2s2
[He] 2s2
The long form electron configuration for carbon is simply 1s2 2s2 2p2. The noble gas shortcut electron configuration for C is [He] 2s2 2p2.