Question

what is quantum numbers
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Answer 1

$\huge{\boxed{\purple{Quantum\;Numbers}}}$

$\bold{\red{Definition;-}}$

• Quantum numbers are intoduced by group of scientists to know the postion on electron in an orbit of an atom

These quantum numbers are of four types

• Principle Quantum number
• Azimuthal Quantum number
• Magnetic Quantum number
• Spin Quantum number

$\large{\boxed{\green{Principle\;Quantum\;number}}}$

• It is proposed by Neil's Bohr
• It is denoted by "n"
• It signifies the size and energy of the orbit
• It has numbers from n = 1,2,3,......
• Maximum number of electrons in a shell can be given by,$2{n}^{2}$
• In a Bohr orbit , the angular momentum of an electron in its $n^{th}$ is given by,
• $mvr\;=\dfrac{nh}{2\pi}$

$\large{\boxed{\green{Azimuthal\;Quantum\;number}}}$

• It is proposed by Sommerfield
• It is denoted by "l"
• The value of l can be given by, they depend on values on n
• l = 0,1,2,......(n-1)
• It indicates the shape of the orbital

$\large{\boxed{\green{Magnetic\;Quantum\;number}}}$

• It is proposed by Lande
• It is denoted by "m"
• It indicates the sub-sub energy levels of the orbital
• The values of of m depends on "l".
• The values of m are from -l to +l
• The total values of m are given by , m = 2l+1
• The number of electrons in s,p,d and f orbital are 1, 3, 5, 7

$\large{\boxed{\green{Spin\;Quantum\;number}}}$

• It is proposed by Goudsmith and Uhlenbeck
• It is denoted by "s"
• It is independent of other quantum numbers
• The values of s are :-
• $\dfrac{1}{2}\;and\;\dfrac{-1}{2}$

• If the electron revolves in anti clockwise then the spin is represented by $\dfrac{-1}{2}$
• If the electron revolves in clockwise then the spin is represented by $\dfrac{1}{2}$
• The maximum number of electrons in an orbital = 2