Silicon (Si) has an atomic number of 14, which means it has 14 electrons. The electron configuration of silicon in its ground state is 1s² 2s² 2p⁶ 3s² 3p².
To determine the number of orbitals occupied by the valence electrons of silicon, we look at the outermost electron shell, which is the third shell (3s² 3p²). The 3s subshell contains one orbital (2 electrons), and the 3p subshell contains three orbitals (6 electrons). Therefore, in total, there are four orbitals occupied by the valence electrons of silicon (2 from the 3s subshell and 2 from the 3p subshell).