Question

Write the number of vertical columns in the modern periodic table. What are these columns called?(Delhi - 2014)

Answer 1

Answer:

18 columns

Explanation:

these columns are called periods

Answer 2

There are 18 numbered columns in periodic table and they are named as groups.

•Periodic table has 18 numbered groups, unnumbered groups belong to f block.

•Columns are the ones containing increasing number of shells.

•Element on top has one shell

while element at last period contains seven shells.

•All the elements of a particular group have same number of electrons in its outermost shell.

•Groups and type of metals in them is written below -

Group 1 alkali metals

Group 2 Alkaline earth metals

Group 3 - 12 Transition metals

Group 13 Boron family

Group 14 Carbon family

Group 15 Nitrogen family

Group 16 Oxygen family

Group 17 Halogens

Group 18 Noble gases.