Question

B. If four elements A, B, C and D are the members
of same period of the Modern Periodic Table and
the order of increasing effective nuclear charge of
them is as follows
A <B<D <C
then choose the correct statement about them.
(1) A, B and C have same valency
(2) Atomic size of B is larger than that of A
(3) Elements B and D both
D both are more
electronegativity than C
(4) Atomic size of A is the largest of them all​

Answer 1

Answer:

4. atomic size of a is largest of them all

Answer 2

The answer is the statement (3).

Explanation:

The effective nuclear charge is in the order $A< B< D< C,$ then we can say that:

• Since the given elements belong to the same period, their valency would not be the same.

Hence, statement (1) is incorrect.

• since A has the least effective nuclear charge, it would have the greatest size, and the size would decrease as the effective nuclear charge increase. So, the order of size would be reverse$, A> B> D> C$

Hence, statement (2) would be incorrect, but statement (4) would be correct.

• An element that has a smaller size or greater effective nuclear charge has a greater electronegativity. So, C would have the maximum electronegativity.

Hence, statement (3) is incorrect.