Question

question.13 (a) What are ‘groups’ and ‘periods’ in the ‘periodic table’?

(b) Two elements M and N belong to group I and II respectively and are in the same period of

the periodic table. How do the following properties of M and N vary?

1. Sizes of their atoms 2. Their metallic characters no

3. Their valencies in forming oxides

4. Molecular formulae of their chlorides​

Answer 1

Answer:

Ex Size of atom of elements decreases from left to right in a period hence atom of element M is bigger than atom of element N.

(b) M is more metallic than N since metallic character decreases as we go along a period.

(c) Group I: Valency 1

   Group II: Valency 2

(d) Formulae of chloride : MCl, NCl2planation:

Answer 2

Answer:

A) Groups and periods are two ways of categorizing elements in the periodic table. Periods are horizontal rows (across) the periodic table, while groups are vertical columns (down) the table. Atomic number increases as you move down a group or across a period.