Q: Given a scientific passage and an answer, generate a question for the given answer.
Passage: The highest-numbered shell is the third shell, which has 2 electrons in the 3s subshell and 3 electrons in the 3p subshell. That gives a total of 5 electrons, so neutral phosphorus atoms have 5 valence electrons. The 10 remaining electrons, from the first and second shells, are core electrons. Answer: five
A:
How many valence electrons do neutral phosphorus atoms have?