Using only Figure 7.16 and the periodic table as a guide, give the complete electron configuration, orbital box diagram, and noble gas notation for vanadium, V.
1s^22s^22p^63s^23p^63d^34s^2 [Ar] 3d^34s^2
Strategy and Explanation The periodic table shows vanadium in the fourth period with atomic number 23. Therefore, vanadium has 23 electrons. Applying Figure 7.16, the first 18 are represented by 1s^22s^22p^63s^23p^6, the electron configuration of argon, Ar, the noble gas that precedes vanadium. The last five electrons in vanadium have the configuration 3d^34s^2. The orbital box diagram shown above follows from the total electron configuration.