A compound decomposes by a first-order process. If 13% of the compound decomposes in 60 minutes, the half-life of the compound is A12
B20
C299
D-18
E-5

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.