state the classification of modern periodic table .? what are the merits and demerits of modern periodic table?

state the classification of modern periodic table .? what are the meri

1.	state the classification of modern periodic table .? what are the merits and demerits of modern periodic table?
Answer» Elements are CLASSIFIED in mendleeve's periodic table in the order of their increasing atomic masses. merits :- 1. his prediction about discovery of new elements were proved correct. 2. he left gaps in his table so that new elements could be easily fitted. 3. nobel GASES could be placed in his table without disturbing other elements demerits:- 1. he couldn't define the POSITION of hydrogen and isotopes 2. at some places in his table he put the ELEMENT with more atomic mass before the element with less atomic mass.