The correct subscript for the reaction would be two. Oxygen gas exists as a diatomic molecule in nature. Also, the subscript two would balance the reaction. In balancing reactions, it is important that the atoms on each side of the reaction is equal.
This is because ionisation energy increases as we move from left to right in a period. Argon presents in the right most column and Argon is a novel gas and has 8 electrons in outermost orbital. So, it is highly stable. I hope I helped! ^-^
The pressure law states that for a constant volume of gas in a sealed container the temperature of the gas is directly proportional to its pressure. ... This means that they have more collisions with each other and the sides of the container and hence the pressure is increased.
