Question

In the modern periodic table elements are ordered according to

Answer 1

They are order by increasing mass. i just had it on a quickcheck yesterday

Answer 2

increasing atomic numbers!

Answer 3

Looking at the periods For instance 2nd Period:
Li (3) -- Be (4) -- B (5) -- C (6) -- N (7) and so on..
Similarly down the groups For instance group 1A:
Na (11) -- K (19) -- Rb (37) and so on....

Answer 4

Seeker is right.