Rocks and Earth Materials

The Earth's core has a radius of approximately 3500 km and experiences extreme temperatures and pressures. It is primarily composed of nickel (Ni) and iron (Fe), which is why it is commonly referred to as the NIFE layer. Therefore, all the given statements are correct.

The oceanic crust is relatively thin and is mainly composed of silica and magnesium. This composition leads to it being commonly referred to as 'sima' (Si for silica and Ma for magnesium). In contrast, the continental crust is rich in silica and alumina.

Geologically, the Earth is divided into three main compositional layers: the outermost thin crust, the thick silicate mantle beneath it, and the dense metallic core at the center.

Igneous rocks form from the cooling and solidification of molten rock, which is called magma when underground and lava when it erupts onto the Earth's surface.

Sedimentary rocks are formed by the gradual accumulation and compaction of mineral and organic particles over time, which gently buries and preserves organisms. Igneous and metamorphic rocks involve extreme heat and pressure that would typically destroy any fossil remains.

Shale is a fine-grained sedimentary rock formed from the compaction of silt and clay mineral particles. When subjected to heat and pressure, shale can metamorphose into slate, gneiss, or other metamorphic rocks. Marble is also metamorphic, formed from limestone.

A bolt of lightning can reach temperatures of around 30,000 Kelvin (about 53,000 degrees Fahrenheit), which is about five times hotter than the surface of the sun and significantly hotter than the Earth's core (around 6,000 degrees Celsius) or lava.

Earth's crust is the outermost solid shell of our planet and is composed of various types of solid rock, such as igneous, sedimentary, and metamorphic rocks. Magma is molten rock found beneath the crust, and water covers much of the crust but does not make up the crust itself.

Sedimentary rocks are formed over long periods as mineral particles and rock fragments (sediments) accumulate in layers, compress under weight, and cement together. Igneous rocks form from cooled magma, and metamorphic rocks form from heat and pressure deep underground.

Igneous rocks are formed when molten rock (magma beneath the surface or lava on the surface) cools and solidifies. Examples include basalt and granite.

Diamond is a mineral composed of pure carbon arranged in a crystal lattice, making it the hardest known natural substance on Earth. It scores a perfect 10 on the Mohs hardness scale.

Many tropical white sand beaches are composed of calcium carbonate, much of which is excreted by parrotfish. Parrotfish graze on algae growing on coral reefs, grinding up the coral skeleton in the process and excreting it as fine white sand.

The Earth's core is primarily composed of an alloy of iron and nickel. Basalt and granite are rocks found in the Earth's crust, while magnesium is a major component of the mantle but not the primary constituent of the core.

The asthenosphere is hotter than the lithosphere because it lies deeper within the Earth. This higher temperature allows the rock to behave plastically and flow slowly, making it weaker and softer than the rigid lithosphere above it.

Oceanic crust is primarily composed of basalt, which is a dark, fine-grained igneous rock. Other options like limestone are sedimentary rocks, while magnesium and nickel are chemical elements rather than rock types.