Updated on August 6, 2022
Table of Contents
Answer
General guidance
1)Principal quantum number
2)Azimuthal quantum number
3)Magnetic quantum number
4)Spin quantum number
Principal quantum number: It describes the size of the orbital. It is denoted by the symbol (n). It also describes the energy of the orbital. The value of n = 1, 2, 3….
Azimuthal quantum number: It describes the subparts and shape of the orbital. It is denoted by the symbol (l). The value of l can be determined from n.
l 
Subshell 
shape 
s 
Spherical 

1 
p 
Dumb – bell 
2 
d 
Clover leaf 
3 
f 
Complex structure 
Magnetic quantum number: it describes the orientation of orbital in space. It is denoted by the symbol (m_{l}). The range of magnetic quantum number is from –l to +l. l = azimuthal quantum number.
l 
m_{l} 
1 
1, 0, +1 
2 
2, 1, 0, +1, +2 
Spin quantum number: describes the spin of electrons. It is denoted by the symbol (s). The value of spin quantum number should be either.
Stepbystep
Step 1 of 4
The energy of an electron in many–electron atom is described by both principal quantum number (n) and azimuthal quantum number (l). So, the correct quantum numbers are n and l.
The choice, is wrong because it describes the orientation of orbital in space.
The choice, is wrong because it describes the spin of electron in orbital.
Information needed to determine the energy of an electron in many–electron atom:
The energy of an electron in many–electron atom is determined by both principal quantum number (n) and azimuthal quantum number (l).
Step 2 of 4
The size of an orbital can be described by principal quantum number (n) itself. So, the correct quantum number is n.
The option, l is wrong because it describes the shape of the orbital.
The option, m_{l} is wrong because it describes the orientation of orbital in space.
The option m_{s }is wrong because it describes the spin of electron in orbital.
Information needed to determine the size of an orbital:
The size of an orbital is determined by principal quantum number (n).
Step 3 of 4
The orientation of an orbital in space is determined by magnetic quantum number (). Hence, the correct quantum number is .
The option, n is wrong because it describes the size and energy of an orbital.
The option, l is wrong because it describes the shape of the orbital.
The option is wrong because it describes the spin of electron in orbital.
Information needed to determine the orientation of an orbital:
The orientation of an orbital is determined by magnetic quantum number (m_{l}).
Step 4 of 4
The shape of the orbital is described by the azimuthal quantum number (l). So, the correct quantum number is l.
The option, n is wrong because it describes the size and energy of an orbital.
The option m_{l} is wrong because it determines the orientation of an orbital in space.
The option m_{s }is wrong because it describes the spin of electron in orbital.
Information needed to determine the general shape of an orbital:
The shape of the orbital is determined by the azimuthal quantum number (l).
Answer
Information needed to determine the energy of an electron in many–electron atom:
Information needed to determine the size of an orbital:
Information needed to determine the orientation of an orbital:
Information needed to determine the general shape of an orbital:
Answer only
Information needed to determine the energy of an electron in many–electron atom:
Information needed to determine the size of an orbital:
Information needed to determine the orientation of an orbital:
Information needed to determine the general shape of an orbital: