aftab09876Q.13. The atomic number of elements A, B, C, D and E are given below.
Element
A
?
?
D
E
Atomic Number
7
10
12
1
4
19
What are the number of valence electrons in B? Identify the element(s) which
(iii) Will form basic oxide?
(iv) Will show valency three?
(v) Will show greatest tendency to gain electron?
Dear student,
| Group 1 | Group 2 | Group 15 | Group 16 | |
| Period 1 | A | B | ||
| Period 3 | C | D | E |
(iii) Since C and A lie in 1st and 2nd group so these can readily lose electron and thus can form basic oxides.
(iv) We know that elements of 15th group need only three electrons to complete their octet configuration and thus show valency 3. So, D will show valency 3.
(v) We know that tendency to gain electron or electron gain enthalpy increases going right along period and decreases going down the group. Thus, B will show highest tendency to gain electrons
Regards,