Question: how many d electrons are found in cobalt?
Answer: There are 2 's'-type electrons on cobalt's outermost, or valence, shell. But because cobalt's a transition metal, the 7 'd'-type electrons can count as valence electrons, though they rarely react with anything. There's 2 or 9 valence electrons, depending on context. The ground state of Co is [Ar] 4s2 3d7.