Why does Silica content in most magmas range from 45 to almost 80 percent by weight?
A) Silica is very heavy and therefore throws off the percent weight.
B) Silica is made up of silicon and oxygen, two elements most prevalent in the earth's crust.
C) Silica is a very heavy gas.
D) Silica is extremely light.

Question

Quizplus · Accepted Answer

Silica is composed of silicon and oxygen, which are two of the most abundant elements in the Earth's crust. As magma is formed from the melting of rocks in the Earth's crust, it is not surprising that silica content would be high in most magmas.

Why Does Silica Content in Most Magmas Range from 45