|Mendeleev’s Periodic Table||Modern Periodic Table|
|Elements are arranged in the increasing order of their atomic masses||Elements are arranged in the increasing order of their atomic numbers.|
|There are 8 groups||There are 18 groups|
|Each group is subdivided into subgroup 'a' and 'b'||Groups are not subdivided into subgroups.|
|Groups for Noble gas was not present as noble gases were not discovered by that time||A separate group is meant for noble gases.|
|There was no place for isotopes.||This problem has been rectified as slots are determined according to atomic number.|
Answered by Shivani Kumari | 2 years ago
The position of three elements A, B, and C in the Periodic Table are shown below– Group 16 Group 17 - - - A - - B C
(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?