graduation of elements Quiz

The scientist…………….discovered the main energy levels of the atom.

• Moseley

• Bohr

• Hofmann

• Mendeleev

The number of energy levels in the heaviest known atom reaches…..levels till now.

• 5

• 7

• 8

• 10

The number of known elements in the modern periodic table till now is ………….

• 216

• 118

• 316

• 16

The number of elements which exist in nature is……….according to modern periodic table.

• 29

• 118

• 92

• 102

The modern periodic table consists of…………horizontal periods.

• 7

• 10

• 14

• 18

The modern periodic table consists of………vertical groups.

• 7

• 10

• 14

• 18

The modern periodic table consists of…..main blocks.

• 3

• 4

• 7

• 8

The elements which occupy the middle block (d) in the periodic table are called ……………elements.

• transition

• alkali

• acidic

• noble

The transition elements start to appear from the beginning of the period…………….

• second

• third

• fourth

• fifth

The atomic number of an element which lies in group (3A) and period (2) is …….

• 13

• 5

• 7

• 15