Correct Answer: Option A) 1 only
Statement 1: The crust is rich in silica and aluminum (SIAL)- correct
The Earth's crust, particularly the continental crust, is indeed rich in silica (Si) and aluminum (Al)
This composition is often referred to as SIAL (Silica-Aluminum)
The continental crust is composed mainly of granitic rocks which are rich in these elements
Silica and aluminum are lighter elements that "floated" to the surface during Earth's formation
Statement 2: The mantle is composed predominantly of nickel and iron - Incorrect
This statement confuses the mantle with the core
The mantle is primarily composed of silicate minerals rich in magnesium and iron (often called SIMA - Silica-Magnesium)
The mantle contains minerals like olivine, pyroxene, and garnet
It is the core (both outer and inner) that is predominantly composed of nickel and iron (NIFE - Nickel-Iron)
Earth's Layer Composition Summary:
Crust: SIAL (Silica-Aluminum) - lightest layer
Mantle: SIMA (Silica-Magnesium) - intermediate density
Core: NIFE (Nickel-Iron) - heaviest layer
