What is the difference between the modern periodic table and the Mendeleev's original table?

Answer 1

There have been very few changes. The whole column of Noble Gases (Helium, Neon, Argon ...) was missing from his as they were unknown. Also, the Rare Earths (Lanthanum ...) which are so much alike they are commonly shown on another row that is linked to a single location on the table were unknown or thought to be just one or two elements - they are very hard to separate from each other. Of course, all of the very short half-life and man-made elements above Uranium have been added.
As should be famously known, there were several (3?) elements which were unknown at the time for which he left empty slots and made very specific and accurate forecasts of their properties based on the row and column they occupied.

Answer 2

all of us recognize that Mendeleev created the first periodic table yet he left gaps for nevertheless undiscovered aspects.the elements on our periodic table immediately are prepared in an increasing order of their atomic weights and is in graphical style or approach it truly is an same with that of Mendeleev's.there are only left gaps of squares for undiscovered aspects and those are his predictions or theory that once what percentage years, there'll be more suitable aspects to be chanced on which will top off and finished the periodic table of aspects.and the finished table that we are using immediately is now the top results of the predictions of him.there is only a touch distinction because the artwork of Mendeleev grew to grow to be the bases of the subsequent chemists to finish and style a sparkling table of aspects....

Answer 3

The difference between the modern periodic table and the Mendeleev's original table:


"Mendleev arranged the elements in periodic table in terms of ATOMIC MASSES whereas the modern periodic table does it in terms of ATOMIC NUMBERS''

Answer 4

In the days of Mendeleev the radioactive had not been discovered . So ,all elements with Z of 84 and more which are radioactive were not found. for elements 43 Tc = technetium and Z= 61 promethium, there exist also no stable compound and could not be found