Question:
The four quantum numbers for the electron in the outermost orbital of potassium \((Z=19)\) are
The four quantum numbers for the electron in the outermost orbital of potassium \((Z=19)\) are
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For an \(s\)-orbital, \(l=0\) and \(m=0\). Potassium has outermost electron in \(4s^1\).
Updated On: May 7, 2026
- \(n=4,\ l=2,\ m=-1,\ s=+\frac{1}{2}\)
- \(n=4,\ l=0,\ m=0,\ s=+\frac{1}{2}\)
- \(n=3,\ l=0,\ m=1,\ s=+\frac{1}{2}\)
- \(n=4,\ l=3,\ m=-2,\ s=-\frac{1}{2}\)
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The Correct Option is B
Solution and Explanation
Concept:
Quantum numbers describe the shell, subshell, orbital orientation, and spin of an electron.
Step 1: Atomic number of potassium is: \[ Z=19 \] Its electronic configuration is: \[ 1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,4s^1 \]
Step 2: The outermost electron is present in: \[ 4s^1 \]
Step 3: For \(4s\)-orbital: \[ n=4 \] For \(s\)-subshell: \[ l=0 \] For \(l=0\), magnetic quantum number is: \[ m=0 \] For the single electron, spin is generally: \[ s=+\frac{1}{2} \] Therefore, \[ \boxed{n=4,\ l=0,\ m=0,\ s=+\frac{1}{2}} \]
Step 1: Atomic number of potassium is: \[ Z=19 \] Its electronic configuration is: \[ 1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,4s^1 \]
Step 2: The outermost electron is present in: \[ 4s^1 \]
Step 3: For \(4s\)-orbital: \[ n=4 \] For \(s\)-subshell: \[ l=0 \] For \(l=0\), magnetic quantum number is: \[ m=0 \] For the single electron, spin is generally: \[ s=+\frac{1}{2} \] Therefore, \[ \boxed{n=4,\ l=0,\ m=0,\ s=+\frac{1}{2}} \]
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