posted by Kellin .
Compare the present Periodic Table with Mendeleevs original Periodic Table in terms of how it is organized, number of elements, what it looks like, ease of understanding, and information given.
Oh my heavens I am not going to try. Mendelev had no idea of electrons or their arrangements or or how atoms went together and just ordered columns by their chemical properties. It came out amazingly well. I will go look for an article.
Here is a reasonable summary: