It is said that the conventional current flows from the positive terminal to the negative terminal of a battery,which means conventional current is the flow of protons,then is it right to conclude that the protons/nucleus of an atom move physically from the positive terminal to the negative terminal of a battery like the electrons.If not,then why is the conventional flow of electric current defined as the direction of flow of protons?

 

Some chose to designate charge flow according to the actual motion of electrons in a circuit. This form of symbology became known as electron flow notation:

 

 

In conventional flow notation, we show the motion of charge according to the (technically incorrect) labels of + and -. This way the labels make sense, but the direction of charge flow is incorrect. In electron flow notation, we follow the actual motion of electrons in the circuit, but the + and - labels seem backward.