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QJEEM24Ch0482: JEE Main 2024 Chemistry - Class 11 JEEM24Ch0482 Solution: The four quantum numbers for the electron in the outer most…

The four quantum numbers for the electron in the outer most orbital of potassium (atomic no. 19) are

Multiple Choice Options

  • A n=3,l=0, m=1, s=+12\mathrm{n}=3, l=0, \mathrm{~m}=1, \mathrm{~s}=+\frac{1}{2}
  • B n=4,l=0, m=0,s=+12\mathrm{n}=4, l=0, \mathrm{~m}=0, s=+\frac{1}{2}
  • C n=2,l=0, m=0,s=+12\mathrm{n}=2, l=0, \mathrm{~m}=0, s=+\frac{1}{2}
  • D n=4,l=2, m=−1,s=+12\mathrm{n}=4, l=2, \mathrm{~m}=-1, s=+\frac{1}{2}

Step-by-Step Verified Solution

The four quantum numbers for the outermost electron of potassium can be determined by first understanding the electronic configuration of potassium (atomic number 19). The electron configuration is as follows:

1s2 2s2 2p6 3s2 3p6 4s11s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 4s^1

The outermost electron resides in the 4s orbital.

The four quantum numbers are as follows:

Principal quantum number ( nn ): This indicates the energy level or shell number of the electron and for the 4s orbital, n=4n = 4 .

Azimuthal quantum number ( ll ): This indicates the subshell or shape of the orbital. For an ss orbital, l=0l = 0 .

Magnetic quantum number ( mm ): This indicates the orientation of the orbital in space. Since there is only one orientation for ss orbitals, m=0m = 0 .

Spin quantum number ( ss ): This can be either +12+\frac{1}{2} or −12-\frac{1}{2} . Typically, the first electron in an orbital has a spin of +12+\frac{1}{2} .

Thus, the four quantum numbers for the outermost electron of potassium are:

n=4, l=0, m=0, s=+12n = 4, \, l = 0, \, m = 0, \, s = +\frac{1}{2}

This matches with Option B:

n=4,l=0, m=0,s=+12\mathrm{n}=4, l=0, \mathrm{~m}=0, s=+\frac{1}{2}

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