(a) Why do we classify elements ? (b) What were the two criteria used by Mendeleev in creating his Periodic Table ? (c ) Why did Mendeleev leave some gaps in his Periodic Table? (d) In Mendeleev's Periodic Table, why was there no mention of Noble gases like Helium, Neon and Argon? (e ) Would you place the two isotopes of chlorine , Cl-35 and Cl-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same ? Justify your answer.
(a) Why do we classify elements ? (b) What were the two criteria used by Mendeleev in creating his Periodic Table ? (c ) Why did Mendeleev leave some gaps in his Periodic Table? (d) In Mendeleev's Periodic Table, why was there no mention of Noble gases like Helium, Neon and Argon? (e ) Would you place the two isotopes of chlorine , Cl-35 and Cl-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same ? Justify your answer.
Harshit Singh , 4 Years ago
Grade 12th pass
