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EEJ MAIN Chemistry QUESTION #7171
Question 1
What is the correct set of four quantum numbers ($n, l, m_{l}, m_{s}$) for the valence electron of a Rubidium atom ($Z=37$)?
  • $5, 1, 1, +\frac{1}{2}$
  • $5, 0, 1, +\frac{1}{2}$
  • $5, 0, 0, +\frac{1}{2}$✔️
  • $5, 1, 0, +\frac{1}{2}$
Correct Answer Explanation
Rubidium ($Z=37$) has the electronic configuration $[Kr] 5s^{1}$.
  • The valence electron is in the 5s orbital.
  • Principal quantum number ($n$) = 5
  • Azimuthal quantum number ($l$) for s-orbital = 0
  • Magnetic quantum number ($m_{l}$) = 0
  • Spin quantum number ($m_{s}$) = $+\frac{1}{2}$