Question: Answer the following question given this paragraph: Helium may seem to be an exception, since it has only two valence electrons. This has to do with the fact that the n = 1 energy level has one s orbital and no p orbitals. As a result, the first energy level can be completely filled by just two electrons. It is the presence of a filled valence shell that gives noble gases their unusual stability, not anything intrinsic about the number 8. In addition to helium, the first few elements such as lithium, beryllium, and boron, have a particularly stable configuration with a pair of valence electrons rather that an octet. Q: How many valence electrons does helium have? Choices: - Five - six - three - two A:
Answer:
two