Compare and contrast the arrangement of elements in Mendeleev’s Peri

1.	Compare and contrast the arrangement of elements in Mendeleev’s Periodic Table and the Modern Periodic Table.
Answer» 1. Mendeleev's Periodic table: (i) Elements are arranged in the increasing order of their atomic mass. (ii) This table has 8 groups and 6 periods. And each group is subdivided as a A and B. (iii) In this table Hydrogen has no position. (iv) No position for isotopes, because in Mendeleev period these are not discovered. 2. Modern Periodic table: (i) Elements are arranged in the increasing order of their atomic number. (ii) It has 18 groups and 7 periods. (iii) Inert gases are placed in separate group. (iv) In this table a zigzag line separates Metals from Non-metals.

Compare and contrast the arrangement of elements in Mendeleev’s Periodic Table and the Modern Periodic Table.

Answer»

1. Mendeleev's Periodic table:

(i) Elements are arranged in the increasing order of their atomic mass.

(ii) This table has 8 groups and 6 periods. And each group is subdivided as a A and B.

(iii) In this table Hydrogen has no position.

(iv) No position for isotopes, because in Mendeleev period these are not discovered.

2. Modern Periodic table:

(i) Elements are arranged in the increasing order of their atomic number.

(ii) It has 18 groups and 7 periods.

(iii) Inert gases are placed in separate group.

(iv) In this table a zigzag line separates Metals from Non-metals.