Question

If the quantum numbers of the highest energy electron in an atom of an element are given as:

$n=4,l=3,m=+3,s=+\frac{1}{2}$,

then the element belongs to:

• A. p-block
• B. d-block
• C. f-block
• D. s-block

Answer 1

The correct option is C f-block

Here we will have to consider the azimuthal quantum number$\left(l\right)$. Azimuthal quantum number helps us to identify the orbital of the electron and to which block of element it belongs to. If the azimuthal quantum number of an element $\left(l\right)$,

$l=0\to$ valence electron enters into $s$ orbital and element belongs to $s$ block,
$l=1\to$ valence electron enters into $p$ orbital and element belongs to $p$ block,
$l=2\to$ valence electron enters into $d$ orbital and element belongs to $d$ block,
$l=3\to$ valence electron enters into $f$ orbital and element belongs to $f$ block,

Here, in this question $l$ is given as 3. So, the electron enters into $f$ orbital and element belongs to $f$-block.

Hence, the correct option is $\text{C}$