# Quantum numbers associated with electron

I wanted to get your opinion on something. I was given the electron 5p^3 and was told to find the quantum numbers associated with it. I got: n=5 l=1 Ml=1 Ms= +1/2 However, my teacher has told me that I am incorrect and that my magnetic quantum number (Ml) should be -1. Could anyone possibly explain why this may be the case or if my teacher is incorrect. Thank you in advance!

• Do you mean you were given the electron configuration $\mathrm{5p^3}$ ? I don't understand which electron's quantum number you are trying to find. – Shoubhik R Maiti Mar 13 at 23:03
• @ShoubhikRMaiti Yes! Sorry for the notation. I am still trying to look into how to do it on here. – Lulu Mar 13 at 23:05
• $\mathrm{5p^3}$ means there are three electrons. So if it is the ground state atom (i.e. follows Hund's rule) then you will have $\mathrm{n=5}$, $\mathrm{l=1}$ for all electrons. Then for three electrons—($\mathrm{m_l=1,m_s=+1/2}$), ($\mathrm{m_l=0,m_s=+1/2}$), ($\mathrm{m_l=-1,m_s=+1/2}$). All electrons have parallel spin. Are you trying to calculate the total orbital angular momentum quantum number($\mathrm{L}$) for the configuration, by any chance? Because each electron has a different value of $\mathrm{m_l}$. – Shoubhik R Maiti Mar 13 at 23:14
• As for the notation on this site, there is a handy guide here: chemistry.meta.stackexchange.com/questions/86/… – Shoubhik R Maiti Mar 13 at 23:15
• @ShoubhikRMaiti No I am not. Yes that is why I am a little confused on the question itself knowing that there are different values for my magnetic quantum number. However, the way I tried to envision it was if I was trying to draw an orbital diagram of just the electron given and seeing which box is the last arrow drawn present within. I believe that would have been the the third box that would have given me the value of 1 for my magnetic quantum number. – Lulu Mar 13 at 23:23