UPSC 2015 CDS II GK Paper

Oxygen and magnesium elements are found in the highest and lowest quantities, respectively in the crust of the earth. About 98 per cent of the total crust of the earth is composed of eight elements. The following table shows these eight elements by weight in the earth’s crust

S.No	Elements	By Weight (%)
1.	Oxygen	46.60
2.	Silicon	27.72
3.	Aluminium	8.13
4.	Iron	5.00
5.	Calcium	3.63
6.	Sodium	2.83
7.	Potassium	2.59
8.	Magnesium	2.09
9.	Others	1.41