1
The number of elements in Mendeleevs periodic table is........elements
2
The scientist who left vacancies in his table to be filled with suitable discovered elements in future is..............
3
Mendeleev classified the elements of each group into ...........sub groups
4
The nucleus of the atom contains.........
5
The scientist, who discovered that the nucleus of atom contains positively charged protons is..........
6
The scientist ...........had discovered the main energy levels
7
The number of energy levels in the heaviest known atom is.........levels
8
The number of known elements in the modern periodic table till now is........
9
The number of elements which exist in nature is ..........
10
The modern periodic table consists of .......horizontal periods
