The element phosphorus has three electrons in the 3p sublevel. The electron configuration for phosphorus is 1s2 2s2p6 3s2p3, where the 3s2p3 indicates the electrons in the third energy level and the p3 indicates three electrons in that level's p orbital.
The electrons in the third energy level of phosphorus are phosphorus' valence electrons. Two of the valence electrons are located in the 3s orbital, while the other three are found in the 3p orbital. In the first energy level, the s orbital contains two electrons. In the second energy level, two electrons are in the s orbital and six electrons are in the p orbital.