Question

B) Explain two criteria's which were used by Mendeleev to classify elements?
C)Carbon has two isotopes, where are these placed in the Modern Periodic Table?​

Answer 1

Explanation:

B) The two certeria used by Mendeleev to classify the elements in his periodic table are: ... The formulae of the hydrides and the oxides formed by the various elements.

C) Carbon exists as two major isotopes, 12C, and 13C ( 14C exists and has a half life of 5730 y, 10C and 11C also exist and their half lives are 19.45 min and 20.3 days respectively). Each carbon atom has the same number of protons and electrons, 6. 12C has 6 neutrons, 13C has 7 neutrons, and 14C has 8 neutrons and so on.