Question

The reported element Ekamercury with atomic number 112 belongs to the group:
A.IIB
B.IIIB
C.IVB
D.VIB

Answer 1

Hint: We know that modern periodic tables are constructed in which elements are arranged in order of their increasing atomic numbers. The periodic table has vertical rows ( groups) and horizontal rows (periods).

Complete step by step answer:
Let’s discuss the groups and periods of the periodic table. In the periodic table, 18 groups and 7 periods are present. Periodic table is also divided into four blocks, p-block, s-block, d-block and f-block. Group I and II belongs to s block, group 3 to 12 belongs to d-block, group 13 to 18 belongs to p-block and lanthanides are actinides belonging to f-block of the periodic table.
Now, come to the question. We have to identify the group of the element Ekamercury whose atomic number is 112.
First we have to write the electronic configuration of the element.
The electronic configuration of Ekamerury is,
${\left[ {{\rm{Rn}}} \right]^{86}}5{f^{14}}6{d^{10}}7{s^2}$
The presence of d-subshell in the electronic configuration indicates that the element belongs to the d-block of the periodic table.
Now, we have the below formula to calculate the group of Ekamercury.
Group = Number of electrons in (n-1)d subshell + Number of electrons in valence shell
In (n-1)d subshell the number of electrons present is 10 and in the valence shell only two electrons are present. So, the group=10+2=12
element Ekamercury whose atomic number is 112 belongs to group 12 or II B.

So, the correct answer is Option A.

Note:
Modern periodic law states that properties (physical or chemical) of elements are periodic function of atomic numbers of them. The periodicity in the properties of elements placed in any group is due to the repetition of same valence shell electronic configuration after a certain definite gaps of atomic numbers such as ${\rm{2}},{\rm{ 8}},{\rm{ 8}},{\rm{ 18}},{\rm{ 18}},{\rm{ 32}}$.