Question

Beryllium has how many valence electrons in its last ring?

Answer 1

Valence electron

• Valence electrons are electrons that are present in the outermost orbit of an atom or electrons that are present in the last ring or shell of an atom.
• Electron configurations can be used to determine an element's valency.
• An element's electron configuration defines how electrons are distributed in its atomic orbitals.
• Electrons are arranged into sets called shells based on their energy.
• Shells are further subdivided into electron subsets known as subshells.

Valence electrons in the last ring of Beryllium

• The atomic symbol of Beryllium is $\mathrm{Be}$.
• Beryllium has the atomic number $4$.
• The electronic configuration of $\mathrm{Be}$ is as follows:

$\mathrm{Be}=1s^{2}2s^2$

• The total number of electrons present in the outermost shell $2s$, is $2$.

Therefore, the Beryllium has two valence electrons in its last ring.