science

Elements of P-block are arranged in ............................groups.

• two

• five

• six

• eight

The modern periodic table consist of....................horizontal periods.

• 7

• 10

• 14

• 18

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

• 7

• 10

• 14

• 18

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

• transition

• alkali

• acidic

• nobel

The scientist............................discovered the main energy levels.

• Moseley

• Bohr

• Hofmann

• Mendeleev