Will mark What are the trends in reactivity on the Periodic Table and why?
What are the trends in metallic character on the Periodic Table and why?

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.

can you attach the

catya your not at all which answer i've seen you do this on another question!