In the law of the conservation of matter, states the volume of matter throughout the process remains constant. In any particular case, it is closed to the movement of matter. It is mostly on conservation of energy means, that the total mass of the products should consider the sum of the mass, which is the reactant of the event of chemical processes.
Reaction:
In the above equation when we react to from the , it will give . that's why option b is correct.
It would not be gain because it would say +6 instead of -2. Having a -2 charge means it wants to loose 2 electrons so it can form a full shell of 8 electrons. It wants to be inert (stable).
- Hope that helps! Please let me know if you need further explanation.
