Question

2)a) By referring the following modern periodic table find out the groups to which the given elements belong
Elements Atomic radius (pm)
K 231
Na 186
Rb 244
Cs 264
Li 152
(b) Arrange the above elements vertically downwards in an increasing
order of atomic radii.
(c) Does this arrangement match with the pattern of the group 1 of the
modern periodic table.
(d) Which of the above elements have the biggest and the smallest atom?
(e) What is the periodic trend observed in the variation of atomic radii
down a group?​

Answer 1

Answer:

Answer:yes, above answer is absolutely right

☝️☝️

Answer 2

Answer:

a) The elements given in the question belong to group 1

b) Increasing order of their atomic radii Li<Na<K<Rb<Cs

c) They exactly match with the group 1 element of the modern periodic table.

d) Cs is the biggest atom and Li is the smallest atom

e) Down a group the atomic radii increases

Explanation:

a) The elements given in the question belong to the first group of the periodic table. They are alkaline metals

b)  The given elements are arranged in the increasing order of their atomic radii as follows:

Li

Na

K

Rb

Cs

c) Yes the pattern match with pattern of group 1 of the modern periodic table

d)The biggest atom is Cs and the smallest atom is Li

The electronic configuration of Li is $1s^22s^1$ so it has two shells

The electronic configuration of Cs is $[Xe]6s^1$ so it has 6 shells.

e) In the group the size of the element increases from top to bottom. As the atomic radii increase down a group the electronegativity of the element decreases.