(a) Which two criteria did Mendeleev use to classify the elements in his periodic table ?
(b) State Mendeleev's periodic law.
(c) Why is it not possible to give a fixed position to hydrogen in Mendeleev's periodic table ?

Sate Mendeleev periodic law ?

(a) Which two criteria did Mendeleev use to classify the elements in his periodic Table? (b) State Mendeleev's periodic law. ( c) Why could no fixed position be given to hydrogen in Mendeleev's Periodic Table ? (d) How and why does the atomic size vary as you go (i) from left to right along a period (ii) down a group ?

No fixed position could be given to hydrogen in Mendeleev's Periodic table

Justify the position of Hydrogen in the periodic table.

Give four defects of Mendeleev's periodic table.

Give any two features of Mendeleev's periodic table.

Mendeleev periodic table was based on

Give three defects of mendeleev's periodic table.

Mendeleev left some gaps in his periodic table.