I've got an assignment to do for chemistry, and it's the history of the periodic table, and I've got quite far on it, but I'm stuck on the similarities and differences.
For similarities I have that they're separated into rows and columns, and are arranged by atomic weight, and for differences I have that the original table didnt have groups or periods, the lanthanoid and actinoid series werent there, and that the elements werent categorised so specifically.
But now i'm stuck
So I was just wondering if anyone could give me a hand with the similarites and differences, because I really can't think of any more .
Thanks.
