What elements in the building block for all other elements

Chlorine, oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, hydrogen, phosphorous and carbon make up over 99 percent of the earth's crust, atmosphere and oceans (by weight). These elements are truly "building blocks"-they combine with other elements to form our world.

Of the 92 natural elements, 25 are essential for life. There are six main elements that are the fundamental building blocks of life. They are, in order of least to most common: sulfur, phosphorous, oxygen, nitrogen, carbon, and hydrogen.