Question

mendlev v/s modern table

Answer 1

Mendeleev

Based on atomic mass

Does not tell why element in a group having similar chemical property

Doesn't explain the reason of periodicity

Doesn't tell us why the properties of element r repeated after2,8,18,32

Has a no. Of anomalies

Modern periodic table

Based on atomic number

Tell all the reasons

No annomalies

Answer 2

Mendeleev Periodic Table--

•)It was based on atomic mass.

•) Position of hydrogen wasn't clear.

•) Metals and non metals were not divided.

•) Provision for isotopes wasn't there.

Modern Periodic Table--

•)Based on atomic no.

•) Position of hydrogen was clear.

•)Metals and non metals were divided.

•)there was Provision for isotopes.

Hope it helps...!!!!!!