Yes, protons have positive charge. But, as has been pointed out many times, changing the number of protons in the nucleus changes the identity of the element. Instead, electrons are exchanged between atoms. Any atom (or molecule) with an equal number of protons and electrons in it will be neutral, any atom (or molecule) with more electrons than protons will be negatively charged (magnitude of charge scales linearly with the difference is), and any atom (or molecule) with fewer electrons than protons will be positively charged (again magnitude of charge scales linearly with the difference is.)Like I said in another of your threads, the number of protons in a given element never changes. Nitrogen always has 7 protons, regardless of what molecule it is in or what its electric charge is. The number of protons is what defines the element. If the number of protons was different, it would no longer be nitrogen.I also agree with you but I am confused about why N got positivie charge on it. As I know positive charge means proton. one positive charge means one extra proton. could you explain it, please?
Note that it is also possible to add one or more protons to an atom (or molecule) without changing the element. each proton just has to be its own nucleus, ie a H+ ion. Chemists and biologists will often talk about the "protonation state" of a species, meaning how many of theoretically exchangeable protons are still on there.