Atomic number is same as the number of protons in the element which is further equal to the number of electrons. As the number of electrons increases in the element, the atomic number of the element also increases.
In periodic table, elements are arranged in the groups, and these groups are columns starting from 1 to 18, elements are arranged in increasing order of atomic number. Elements are placed with difference of one atomic number.
First four elements present in the periodic table is:
\(He\) atomic number is one (1).
\(H\) atomic number is two (2).
\(Li\) atomic number is three (3).
\(Be\) atomic number is four (4).
Thus, the series of atomic numbers that represents the ordering of consecutive elements within the periodic table is the last option - 1, 2, 3, 4...
