Question

(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?

Answer 1

By the atomic weight and the atomic radius

Answer 2

By the atomic weight and the atomic radius