23 V Vanadium 50942 2 8 11 2. Periodic Table of Element Groups. File Electron Shell 020 Calcium Svg Wikimedia Commons Potassium Atom Electron Configuration Atomic Structure Also a single glutaraldehyde molecule may form direct cross links if the steric arrangement of adjacent peptides allow it. . Also the real electron configuration of an atom may differ from the prediction because of relativistic effects shielding etc. When an oxygen atom forms a single chemical bond it shares one of its own electrons with the nucleus of another atom and receives in return a share of an electron from that atom. Element Calcium Ca Group 2 Atomic Number 20 s-block Mass 40078. An electron shell is the set of allowed states that share the same principal quantum number n the number before the letter in the orbital label that electrons. Electron configuration was first conceived under the Bohr model of the atom and it is still common to speak o