Question

There are over 100 elements in the universe. In the earth's crust and upper mantle, which statement is most accurate about the elements found there?
A) Carbon is in all compounds found in the earth.
B) Most of the earth is made up of only a few elements.
C) The earth's crust and upper mantle is made up of only 4 elements.
D) All the elements can easily be found anywhere in the crust and upper mantle.

Answer 1

the answer is B: Most of the earth is made up of only a few elements.

Answer 2

The correct answer is option B, Most of the earth is made up of only a few elements

Reason -

The material that commonly exists in earth are as follows:

a) Crust – It is made up of 46.6 % of oxygen by weight, 27.7 % of silicon by weight, 8.1% of aluminium by weight, 5% of iron by weight, 3.6% calcium by weight, 2.8% sodium by weight, 2.6% of potassium by weight etc.  

b) Mantle – it is majorly composed of silicate rocks rich in magnesium and iron

c) Core – The core is mainly made up of nickel iron alloy.  

It  can be clearly visualized that most of the Earth’s layer are composed of majorly few elements like silicon, iron, magnesium, nickel etc.