Oxygen and silicon are the light elements that rose to the surface to form Earth's crust, with oxygen being most abundant, followed by silicon. These elements make up the majority of the rocks composing the crust, which is the planet's outermost layer.
The two light elements that float towards the surface to create the crust on Earth are oxygen and silicon. The crust is a thin layer of rock that forms the outer surface of Earth, and through a process known as planetary differentiation, these lighter elements rose towards the Earth's surface. Heavier metals sank toward the core during Earth's early formation while lighter silicates, which compose rocks like basalt and granite, ascended to form the crustal material.
The crust is further divided into oceanic and continental types, with oceanic crust mainly composed of basalt and continental crust mostly composed of granite. The two most abundant elements found in these rocks that make up the Earth's crust are oxygen, making up 47% by weight and 94% by volume, and silicon, which accounts for approximately 28% by weight and 1% by volume.
In conclusion, the Earth's crust formed from the lighter silicates, predominantly oxygen and silicon that floated upwards during the planetary differentiation, leaving a thinner, less dense layer covering the Earth's surface.