State Mendeleev's 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 is it not possible to give a fixed position to hydrogen in Mendeleev's periodic table ?

(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 ?

State Mendeleev's period law.

Sate Mendeleev periodic law ?

State Modern Periodic Law ? Why is it considered better than Mendeleev's periodic law for the classification of the elements ?