Consider the elements N, P, O, S, Cl and F. The number of valence electrons present in the elements with most and least metallic character from the above list is respectively.
- 7 and 5
- 6 and 7
- 5 and 7
- 5 and 6
Answer
(3) 5 and 7
Solution
Metallic character decreases along a period (left right) and increases down a group.
Period 2: N, O, F; period 3: P, S, Cl.
Most metallic: P (period 3, group 15); least metallic: F (period 2, group 17).
P: [Ne] 3s2 3p3 5 valence electrons
F: [He] 2s2 2p5 7 valence electrons
Answer: (3)