can u answer this question ???

Question

the element Oxygen is a gas that makes up about 20 percent of the earth's atmosphere. Oxygen also is the most abundant element in the earth's crust, yet earth's crust is not a gas. explain this apparent conflict??/

Answer 1

It is in the earths crust as compounds with silica, aluminum, iron and other elements.
Oxides as percentage of earth's crust:
SiO2 59.71 %
Al2O3 15.41 %
CaO 4.90 %
MgO 4.36 %
Na2O 3.55 %
FeO 3.52 %
K2O 2.80 %
Fe2O3 2.63 %
H2O 1.52 %
TiO2 0.60 %
P2O5 0.22 %
total 99.22 %

Answer 2

The oxygen is combined either with Silicon making up sand or metals forming their ores.

Si is the second most abundant element in the Earth's crust and SiO2 is the constituent of almost all of the lithosphere.