Q. Consider the following elements of the earth’s crust:
1. Oxygen
2. Silicon
3. Aluminum
4. Iron
Which of the following code is correct ascending order of elements of the earth’s crust?

[A] 1-2-3-4

[B] 2-3-4-1

[C] 4-3-2-1

[D] 3-2-4-1

Answer: C


  • The earth is composed of various kinds of elements. These elements are in solid form in the outer layer of the earth and in hot and molten form in the interior.
  • About 98 per cent of the total crust of the earth is composed of eight elements like oxygen, silicon, aluminium, iron, calcium, sodium, potassium and magnesium and the rest is constituted by titanium, hydrogen, phosphorous, manganese, sulphur, carbon, nickel and other elements.
  • The Major Elements of the Earth’s Crust Elements By Weight (%):
  • Oxygen- 46.60
  • Silicon- 27.72
  • Aluminum- 8.13
  • Iron- 5.00
  • Calcium- 3.63
  • Sodium- 2.83
  • Potassium- 2.59
  • Magnesium- 2.09
  • Others- 1.41

Source: GC Leong