Well,You have to understand pretty much everything,So look,If you know the number of protons or electron then you will know its atomic number,and if you know the number of protons and neutrons then you will know the mass of the element.So yeah,this is basically all you need to know to understand the unified structure of atom to help you better understand an element that was unfamiliar to you!
Explanation: As we know that atom was used to be known as the smallest indivisible particle but not now, as they consist of small microscopic particles which are known as electrons , protons and neutrons.
Thus atom consist of protons, neutrons and electrons wherein electrons are negatively charged, protons are positively charged and neutrons are neutral in nature.
Thus in order to understand the nature of element, we must know the number of electrons and protons and neutrons present in that element. Thus this could also help us in understanding the better way of unified atom.
