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Formation of anion

Atoms Molecules Ions Chemical Equations On-line practice




Add 2 electrons






Oxygen ( Group 6 )

No. of electrons : 8

No. of protons : 8

bulletOxygen has 2 orbits.  The second orbit has 6 electrons.
bulletFor oxygen to be stable, it can either give away all the 6 electrons on the second orbit OR it can receive 2 more electrons from another atom.
bulletBoth processes will lead to oxygen having 8 electrons on its outer orbit.
bulletHowever, receiving 2 more electrons from another atoms is more favourable than giving away all its 6 electrons.
bulletTherefore, oxygen will receive 2 more electrons which means it now has 10 electrons and 8 protons.
bulletThis makes oxygen to have a negative charge.
bulletO + 2e --> O 2-


Other common anions :

Cl + 1e -->  Cl -

S + 2e -->  S 2-


Formation of cation ] [ Formation of anion ] Formation of compounds ]