Question

the pie chart below shows the percentage of the most common elements in the surface layer of the earth (called the crust). we have been reading about the silicate minerals, and learned that the backbone of the silicate minerals is made up of silicon and oxygen atoms in the shape of tetrahedra. to see how important these two elements are, add together the percentages of the elements silicon (si) and oxygen (o) that make up the crust. what is the total?

Explanation:

Step1: Identify percentages

Identify the percentage of silicon and oxygen from the pie - chart. Silicon is 27.7% and oxygen is 46.6%.

Step2: Calculate sum

Add the two percentages together: 27.7%+46.6%.
$27.7 + 46.6=74.3$

Answer:

74.3%