Originally Posted by tara
Thanks! Na ions should just be in vacuum for not reacting with other atoms?
Well, now you should really precise what sort of sodium ions we're speaking about. If it's in water, then you have water molecules around it which makes is so you have 'free' Na ions.
Otherwise, even in a vacuum, it would have to be kept with an electric field. As the ions are charged, they will tend to snatch electrons from the walls of whatever container they are in to attain electronic stability. But assuming it's inert, then yes.
Then why Na can be stored in mineral oil and it doesn't react with it?
Remember that when there is a chemical reaction, the properties of an element might change. In this case, you're comparing a neutral atom with its ion!
Or if you want, the Na ions are in a sea of electrons, as sodium is a metal and the oil does not take the electron (or maybe it requires far too much energy to do so). Hence the Na ions remain with the electrons and no reaction occurs.
when Na turns to Na+ and electron , the electron has the energy that is released when Na reacts with for example Cl?
The electron does not have the energy strictly speaking. It is the reaction of the electron plus a chlorine atom which releases part of the energy. Chlorine is much more stable with a complete octet.
And then, additional energy is released when the positive Na ion and the negative Cl ion bind together.
Together, they are larger than the energy required initially for ionisation. Now imagine you do such a reaction. Only a little energy is needed to start that reaction and this can be obtained from the heat from the environment itself. Assuming that only one atom reacts, this will produce a lot of energy which will cause adjacent atoms to react.
And this goes on and on until everything reacted. Conclusion, only a small energy was required and in the end, a lot of energy was released, significantly much more.