[id8899]

Hi

I have a question I don't understand:
What is the maximum number of electrons in Thallium atom,  that - ml = -2
The correct answer is 4, but I don't understand why?

thanks 

[Hunter2]

What does -ml = -2 mean.

Thallium stands in the 3. Maingroup and has 3 outer valence electrons. Compounds are Tl⁺ and Tl³⁺

So I also dont understand what the 4 mean.

[mjc123]

Are you referring to the quantum number m_l, the z-component of the orbital angular momentum?
Thallium has 4 filled levels with l≥2: 3d, 4d, 5d and 4f. Each of these will have two electrons with m_l = -2, one spin-up and one spin-down. So the answer should be 8. Who says it is 4?