Destroyer #62

[Fancy312]

Hi Guys,

Just had some confusion with this one, if anyone can help me out step by step for this i would really appreciate it!

62. Barium is an alkaline earth metal with the atomic number 56 . Which set of quantum numbers may be written for a valence electron of Barium?

I got that it was in row 6, so n=6, then when they pick [Xe] 6s2, but I didn't get what the 1=0 m1=0 and ms= 1/2 meant,

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[DentalNucleicAcid]

Barium's 2 valence electrons are in the 6s orbital (it's in the 6th row of the s-block). So n=6 because of the "6" in "6s". l=0 because of the "s" in "6s". l is the azimuthal quantum number. Here are the rules for l--> s=0, p=1, d=2, f=3. That's where the 0 came from, because s=0. Next, ml=0 because ml can only be any number from -l to +l <-- those are L's, not one's). Since l=0, ml has to be 0 because of this rule. ms can either be +1/2 or -1/2, but they'll only give you one of those options for ms on the test.

 

[Fancy312]

@DentalNucleicAcid thank you so much for your explanation, makes sense now