The most abundant element in the silicate Earth is oxygen. In fact, it’s not much of an exaggeration to say that the Earth is a closest-packed array of O atoms. The other atoms squeeze in the spaces between them.
The tables give some determinations of the cosmic abundance of elements (Table 2-1), determined largely by spectroscopic studies of the Sun. Table 2-2 gives a simple Earth model based on those cosmic abundances. Table 2-3 shows some estimates of the composition of the continental crust. Those require knowing the relative abundance of the various rock types that make up the crust.