What happens when chlorine form an ion is that it gains an electron and has an octet in its outer shell ( answer A)
<u><em> Explanation</em></u>
<u><em> </em></u>Chlorine is is in atomic number 17 in periodic table.
The electron configuration of chlorine is 1S2 2S2 2P6 3S2 3P5 or[Ne]3S2 3p5 or 2.8.7.
chlorine therefore has 7 valence electron therefore it gain 1 electron to form Cl- ( ion)
Cl- has 8 electron in its outer shell ( it obeys octet rule of eight valence in outer shell.
In every reaction, mass cannot be destroyed nor created as defined by the law of conservation of mass. Energy also cannot be destroyed when a chemical reaction takes place