Question

In the following table, six elements A, B, C, D, E and F (here letters are not the usual symbols of the elements) of the modern Periodic Table with atomic numbers 3 to 18 are given:

3	4	5	6	7	8	9	10
A					E		G
11	12	13	14	15	16	17	18
B	C		D			F

(a) Which of these is (i) a noble gas, (ii) a halogen? 

(b) If B combines with F, what would be the formula of the compound formed? 

(c) Write the electronic configurations of C and E.

Answer 1

(a) (i) G with atomic number 10 is a noble gas because it has complete octet. 

(ii) F with atomic number 17 is a halogen. 

(b) B with atomic number 11 has 1 valence electron and F with atomic number 17 has 7 valence electrons so the formula of the compound formed would be BF. 

(c) Electronic configuration of C and E are 

E₈- 2, 6 

C₁₂- 2, 8, 2