Question

Ques 3 distinguish between;-
1Sial and Sima
2Intrusive and extrusive igneous rocks.
3 Crust and core
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Answer 1

Answer:

1. Answer. Sial is composed of silicon and aluminium.It is upper layer which forms a discontinuous cover over the Earth's crust and is entirely absent the ocean floor. Sima is composed of silicon and magnesium. This is the second layer below sial which forms the ocean base.
2. Intrusive igneous rocks cool from magma slowly because they are buried beneath the surface, so they have large crystals. Extrusive igneous rocks cool from lava rapidly because they form at the surface, so they have small crystals.
3. Outer one is the Crust which is cold and solid, it floats on Mantle (Asthenosphere). Mantle is the middle layer, it is semi solid, viscous. It has two parts upper and lower mantle. Core is the inner most part, made mostly of nickel and iron.

Answer 2

Answer:

hello friend here is your answer

Explanation:

sial=sial means silica and alumina makes sial (si-silica and al-alumina)

sima= silica and magnesium makes sima

(si-silica and ma-magnesium)