The chemical formula of the oxide of a metal element M is mcl3 It's better to solve it now
ALCl3
FeCL3
The chemical formula of the compound composed of the most metal and nonmetal elements in the earth's crust is______ .
The most abundant metallic element in the crust is al, and the most abundant non-metallic element is o. the valence is + 3 and - 2 respectively, so the compound they are composed of is Al2O3