Atomic Structure and Chemical Bonding — Question 25

(a) (i) Atom E.

As its atomic number is given as 7, therefore it contains 7 protons.

(ii) Atom B.

As its atomic number is 9, hence it has 9 electrons, therefore, its electronic configuration is 2, 7.

(b) Atom C has electronic configuration : [2, 1]

Atom D has electronic configuration : [2, 6]

As D requires two electrons to complete its octet, hence, it combines with two atoms of C which donate their valence electrons to attain stable noble gas configuration and D accepts the two electrons and attains a stable state, hence the formula of the compound formed between C and D is C₂D

(c) (i) Metals: A [2,8,8,2] and C [2,1]
Reason — As the elements A and C have 2 and 1 electrons respectively in the valence shells hence, they are metals.

(ii) Non-metals: B [2,7], D [2,6], E [2,5].
Reason — As the elements B,D and E have 7,6 and 5 electrons respectively in the valence shell, hence they are non-metals.