Question

What are the values of the quantum numbers of 19th electron of scandium (Z = 21)?
A. \[n = 4\]; \[l = 0\]; \[ m = 0\]; \[ m_s = \dfrac {1}{2} \]
B. \[n = 4\]; \[l = 1\]; \[ m = 0\]; \[ m_s = \dfrac {1}{2}\]
C. \[n = 4\]; \[l =2\]; \[ m = 1\]; \[ m_s = \dfrac {1}{2} \]
D. \[n = 4\]; \[ l =3\]; \[ m = 2\]; \[ m_s = \dfrac {1}{2} \]

Answer 1

Hint: Scandium has a wide range of characteristics, and its applications have been studied. Some of the qualities distinguish scandium from other elements, and they determine the element's many purposes and applications. In this field, more research is being done to identify new scandium features and applications.

Complete answer:
The electronic configuration of scandium ($Z = 21$) is $1s^2 2s^2 2p^6 3s^2 3p^6 3d^1 4s^2$.
The 19th electron of scandium enters 4s orbital. Hence, are \[n=4\].
For an electron in s orbital \[l=0\]; \[m=0\].
Hence, the values of the quantum numbers of $19^{th}$ electron of scandium are \[n=4\]; \[l=0\]; \[m=0\]; $m_s =+ \dfrac{1}{2}$
Therefore, the correct answer is “Option A”.

Additional Information:
Scandium is a chemical element that is also a rare metal on the planet. A Russian chemist, Dmitry Ivanovich Mendeleyev, predicted the presence of this element in 1871. Lars Fredrik Nilson was the one who discovered it in 1879. The letter "\[Sc\]" is used to signify it. Scandium has the atomic number 21 in the periodic table. On the other hand, the atomic weight is 44.965 g/mol. Scandinavia is the most prevalent place on Earth where scandium, or "\[Sc\]," is found. It can be found in trace amounts in many mineral types on the planet. The element scandium has a variety of characteristics and applications.
It is a chemical that is thought to be non-toxic. Scandium has not been the subject of much comprehensive investigation in terms of health and safety concerns. Scandium chloride is a poisonous chemical with a fatal dose. As a result, this chemical, as well as other scandium compounds, should be treated with caution because they have a moderate toxicity.

Note:
Scandium is also one of the expensive elements due to its scarcity and limited production. The price of pure scandium can be approximately \[7000\] per kg even higher than that. Scandium has a high cosmic abundance as well. Also, it is the twenty-third (23rd) most abundant element in the sun.