Four elements A,B,C, and D have atomic numbers 12, 13, 14 and 15 respectively.
Answer the following questions giving reasons:
a. What is the number of valence electrons and valency of D?
b. Which of them will have largest atomic radii?
C. which of these elements will form the most basic oxide?
(a) Electronic configuration of element D is
D15 = 2, 8, 5
Element D has 5 valence electrons and its valency is 3 because it requires 3 electrons to acquire inert gas configuration.
(b) A12 = 2, 8, 2
B13 = 2, 8, 3
C14 = 2, 8, 4
D15 = 2, 8, 5
Since these elements are belong to same period because all elements have same shells and we know that radius of elements decreases from left to right in a period so element A will have largest radius.
(c) We know that metallic oxides are basic in nature and metallic nature decreases from left to right in a period so element A will form the most basic oxide.