Comprehension given below is followed by some multiple choice questions. Each question has one correct option. Choose the correct option.
In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz s, p, d and f.
The modern periodic table consists of 7 periods and 18 groups. Each, period begins with the filling of a new energy shell. In accordance with the Aufbau principle, the seven periods (1 to 7) have 2, 8, 8, 18, 18, 32 and 32 elements respectively.
The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthonoids and actinoids are placed at the bottom of the main body of the periodic table
(iv) The electronic configuration of the element which is just above the element with atomic number 43 in th same group is ...........

Options

A. `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3d^(5) 4s^(2)`
B. `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(5) 4s^(3) 4p^(6)`
C. `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(6) 4s^(2)`
D. `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(7) 4s^(2)`

Answer

A

Explanation

The fifth period begins with Rb (Z = 37) and ends at Xe (Z = 54), Thus, the element with Z = 43 lies in the 5th period. Since, the 4th period has 18 elements, therefore, the atomic number of the element which lies immediately above the element with atomic number 43 is 43 - 18 = 25
Now, the electronic configuration of element with Z = 25 is
`1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(5) 4s^(2)` (i.e., Mn).