Question

Pls ans this!! Chem qn( periodic classification of elements)

Answer 1

Answer:

Lag raha hai sabhi ki yehi phati hai

Step-by-step explanation:

(a) A

Atomic number of A = 19

Electronic configuration of A = 2,8,8,1

Therefore, belongs to group 1 which no other element does(since it has only 1 valence electron)

Thus, A is the most electropositive

(b) D

Atomic number of D = 18

Electronic configuration of D = 2,8,8

Since the Outer shell of D is completely filled

Therefore it is the noble gas

(c) B

Atomic number of B = 14

Atomic number of silicon = 14

Therefore B is Silicon

Since Silicon is a metalloid

Therefore, B is the metalloid

(d) C

Atomic number of C = 8

Electronic configuration of C = 2,6

Valency of C = 8 - 6 (since the valence electrons are >4, therefore, we do 8 - V.E. to find the elements valency)

Valency of C = 2

Since C will require 2 electrons to complete its octet, therefore it is the right answer

(e)  A₂C

Atomic number of A = 19

Electronic configuration of A = 2,8,8,1

Valency of A = 1

Valency of C = 2 (from part (d))

Therefore, the compound formed is A₂C (since valency of C will be the number of Atoms of A and visa-versa)

(f) B and D

Atomic numbers of the given elements :

A = 19

B = 14

C = 8

D = 18

Electronic configuration of given elements:

A = 2,8,8,1

B=2,8,4

C=2,6

D=2,8,8

For 2 elements to be in the same period, their number of shells must be equal

Thus, we see that B and D are the only given elements with the same number of shell

Therefore, B and D belong to the same group

hopefully I got it right

The number in the subscript behind the Element is its atomic number and superscript is its mass number (in atomic mass units)

Also, the question does not mention that writing the explanation is compulsory so even if you didn't write the explanation, you would still get marks

HOPE IT HELPS