The elements in the periodic table were arranged with the increasing order of their atomic number.
Step-by-step explanation
The periodic table consists of elements present in the earth surface.
The arrangement of all elements are done from the lowest to highest order of atomic number from left to right of each row.
Each row is defined as period which consists of increasing atomic number.
Similarly in that way the next row starting element will be having more atomic number than the element in its front.
So in this way the arrangements of elements are done based on their atomic number.