Please help in some questions.
1. if we remove one proton and electron from an atom than that proton and electron become hydrogen atom as hydrogen atom contain only one proton. 2. Number of proton is equal to number of electron in an atom than why some atom contain different amount of electrons. 3. what is unstable atom. 4. why c-12 taken as standard mass in place of hydrogen. Hydrogen has one unit mass. So why hydrogen should not be used as standard mass
Basically, because "Why not?". Somethingneeds to be the standard. Carbon-12 is fairly common, and it's not oxygen(which was the previous standard; unfortunately, some people took naturally occurring oxygen as the standard and others took oxygen-16 specifically.)Indeed, the standard was changed from oxygen to be a compromise between the chemists and physicists who used the differing definitions for Oxygen.It is not Hydrogen because it was not easy to use experimentally to compare elements.