Question

in which orbitals would the valence electrons for selenium (se) be placed?
s orbital and f orbital
s orbital only
s orbital and p orbital
d orbital only

Explanation:

硒（Se）是第34号元素，其价电子构型为$4s^{2}4p^{4}$，价电子分布在s轨道和p轨道。

Answer:

C. s orbital and p orbital