Final answer:
A neutral atom with the given electron configuration has six valence electrons, which belong to the element sulfur.
Step-by-step explanation:
A neutral atom with the electron configuration 1s22s22p63s23p4 has six valence electrons. The electron configuration corresponds to the element sulfur (S), which is in Group 16 of the periodic table. The valence electrons are the electrons in the outermost shell, which can be seen from the configuration to be the 3s and 3p orbitals. In this configuration, 3s23p4 accounts for the six valence electrons present in a neutral sulfur atom.