Answer is: elements are organized by proton arrangement, which determines behavior.
There are 118 unique substances (elements) arranged on an amazing chart that reveals their hidden secrets to anyone who knows how to read it.
The first chemical element is hydrogen (atomic number is 1) and the last is oganesson (atomic number is 118).
Elements are scheduled in periodic table, ordered by their atomic number.
Metals lost electrons and form cations, nonmetals gain electrons and form anions.
For example, group 1 of Periodic table of elements (alkaline metals). Alkaline metals are lithium, sodium, rubidium, potassium, cesium. They have low ionization energy and lose one electron very easy.