Attempts of elements classification

1. The number of elements in Mendeleev's periodic table is ...... elements.

• 118

• 67

• 92

The scientist who left vacant in his table to be filled with suitable discovered elements in future is________

• Mendeleev.

• Rutherford

• Moseley.

Mendeleev classified the elements of each group into ........ sub-groups.

• 4

• 3

• 2

The number of energy levels in the heaviest known atom is levels

• 7

• 8

• 9

The number of known elements in the modern periodic table till now is______

• 118

• 67

• 76

The elements, which occupy the middle of the periodic table are called ________elements.

• alkaline earth

• alkali

• transition block (d)

Elements of d-block are arranged in______groups

• 12

• 6

• 10

If the atomic number of an element is 15. so its group is located in _______ block.

• s

• p

• d

Lanthanides and actinides are located in the ______ block

• f

• d

• p

Noble gases are located in group________

• 0

• 8

• 18