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

Answer 1

The Periodic Table is now complete and can be displayed using the integral atomic numbers. In Mendeleev's time there were still unknown elements. In fact, one of the primary uses of his table was to predict the properties of elements that had not yet been isolated. (His 1869 table included speculative names for some expected elements.)

-- In Mendeleev's periodic table, transition elements were placed in another group.

--In Mendeleev's periodic table, noble gases were written on left side. In the modern periodic table, noble gases are written on right side.

Answer 2

The mendeleevs periodic table was classified according to the atomic weight of elements and the modern periodic table is classified according to atomic no. Mendeleeves peiodic table failed as there was no space for isotopes in his periodic table which have different atomic weight. This problem wont occur in modern peridic table bcoz isotopes have same atomic no.

Answer 3

Mendeleev ordered the elements in his periodic table according the Atomic Mass of the element, whereas the modern day periodic table has the elements ordered according to their Atomic number (or the Proton Number).

However there is not really any difference between Mendeleev's periodic table and the modern periodic table because there were only 3 places where the atomic weight order differs from the atomic number order.

With Te -- tellurium and I -- iodine, Mendeleev put the elements in his table in the right order, wrongly insisting that there must be an error in the accepted atomic weight of tellurium.

With Co -- cobalt and Ni -- nickel, the atomic weights were similar enough that Mendeleev could slot the elements in in the right order by assigning the two elements the same atomic weight, because at the time the error margin in these atomic weights allowed for this to be done.

With Ar -- argon and K -- potassium, there was no real problem because argon was not isolated until 1894, and did not need to find a slot in the periodic table until 1899 when the other 4 noble gases had been discovered and recognised as chemical elements.

Answer 4

To put it simply it just has more on it. Medeleev's arangement has not been changed - if you want to know how he aranged it try: http://searchwarp.com/swa472840-A-Brief-Look-At-The-Periodic-Table-Of-Elements.htm by Connor Davidson

Answer 5

Not all the elements were included.

The modern Periodic Table is arranged in order of increasing atomic number unlike Mendeleev's table which was arranged in order of increasing atomic mass.

Answer 6

In Mendeleev's periodic table, the elements were arranged according to increasing atomic mass and repeating periodic properties.

In modern periodic table, the elements were arranged according to increasing atomic number and repeating periodic properties.

Answer 7

Mendeleev arranged the elements in the increasing order of atomic mass and repeating properties.

In the modern periodic table the elements are arranged in the increasing order of atomic number and repeating properties.

Answer 8

mendeleev's was organized by atomic mass and not atomic number.

Answer 9

Acc. To mendeleev the elements are classified by atomic mass whereas in modern periodic table elements r claassified acc. To its atomic no..

Answer 10

differences*