How many groups and periods does modern periodic table have?

What are horizontal rows and vertical columns in a periodic table known as?

How does the electronic configuration in atoms change

(i) in a period from left to right?

(ii) in a group from top to bottom?

Name two elements in each case :

(i) Alkali metals

(ii) Alkaline earth metals

(iii) Halogens

(iv) Inert Gas