Question

The location of elements in the regions of Earth has enormous practical importance.

(a) Define the term differentiation, and explain which physical property of a substance is primarily responsible for this process.

(b) What are the four most abundant elements in the crust?

(c) Which element is abundant in the crust and mantle but not the core?

Short answer

(a). Differentiation is the separation of substances based on their physical and chemical characteristics and the density of a substance is the physical attribute.

(b). Oxygen, silicon, aluminium and iron.

(c). Oxygen (and silicon) is abundant.

Step-by-step solution

Element

An element is a substance with the same number of protons in all of its atoms, or the same atomic number in all of its atoms.

Subpart (a)

(a). The heat from radioactive decay and meteor impacts elevated the Earth's temperature to${10}^4\mathrm{K}$

after the Big Bang, resulting in a molten mass. The differentiation or stratification of the Earth began at this point.

Differentiation is the separation of substances based on their physical and chemical characteristics. Density is the physical attribute of a substance that is primarily responsible for this process. The lighter atoms formed parts of our planet, while gaseous elements like hydrogen and helium were blasted into space.

Earth is made up of layers and is made up of:

•core dense (average density $10-15{\mathrm{gcm}}^{-3}$).

•thick homogeneous mantle-average density $4-6{\mathrm{gcm}}^{-3}$.

thin heterogeneous crust, $2.8{\mathrm{gmcm}}^{-3}$average density.

We can see how the heavier substances "sink" to the centre, resulting in a thick core.

Therefore, density is the physical property.

Subpar (b)

(b). Oxygen, silicon, aluminium, and iron are the four most prevalent elements in the crust.

Subpart (c)

(c). The element oxygen is abundant in the crust and mantle but not in the core (and silicium).