Question

Which of the following is general electronic configuration of 4d series?
A.$4{{\text{s}}^{1{\text{ to 2}}}}{\text{3}}{{\text{d}}^{1{\text{ to 10}}}}$
B.$4{{\text{s}}^{1{\text{ to 2}}}}{\text{4}}{{\text{d}}^{1{\text{ to 10}}}}$
C.${\text{5}}{{\text{s}}^{1{\text{ to 2}}}}{\text{5}}{{\text{d}}^{1{\text{ to 10}}}}$
D.${\text{5}}{{\text{s}}^{1{\text{ to 2}}}}{\text{4}}{{\text{d}}^{1{\text{ to 10}}}}$

Answer 1

we will use the general electronic configuration for the d block element. Putting the value of coefficient of d equals to 4 in the general electronic configuration we will get the electronic configuration of d block element.

Complete step by step solution:
The general electronic configuration for the d block element is ${\text{n}}{{\text{s}}^{1{\text{ to 2}}}}\left( {{\text{n}} - 1} \right){{\text{d}}^{1{\text{ to 10}}}}$. Now since we have given that we need to write the electronic configuration for 4 d series elements so that means 4 d orbital are involved in the general electronic configuration. So this gives us:
${\text{n}} - 1 = 4$
This gives us the value of principal quantum number as: ${\text{n}} = 5$
So putting the value of principal quantum number in the general formula we will get the electronic configuration for the d block elements as:
${\text{5}}{{\text{s}}^{1{\text{ to 2}}}}{\text{4}}{{\text{d}}^{1{\text{ to 10}}}}$

Thus, the correct option is D.

Additional information:
D block elements are the elements from group number 3 to group number 12 of the modern periodic table. The valence electron occupies the d orbital in case of D block elements. They are also known as transition metal elements because they lie in the transition in between s block and p block elements. The elements that are in D block are typically metals which have very good malleability, ductility and high electrical conductivity and thermal conductivity. They have good tensile strength. The most important property that makes d block elements stand out is the property of showing variable oxidation States. Each element can show a range of oxidation States.

Note: In case of the orbital the electrons are filled in the penultimate energy level of the valence shell. As we can see in the above question we have used 5 s orbital but 4 D orbital. 4d orbital will be called a penultimate shell; however it is still a valence shell.