Earth Science

The stratosphere contains the ozone layer, which absorbs most of the Sun's harmful ultraviolet radiation, protecting life on Earth. Other layers like the troposphere, mesosphere, and ionosphere do not have this primary function.

The exosphere begins at about 690 to 1,000 km above Earth's surface and extends outward to roughly 10,000 km, marking the outermost layer of the atmosphere where atmospheric particles can escape into space. The other options correspond to lower atmospheric layers at much lower altitudes.

The color of sedimentary rocks is primarily influenced by the presence of iron compounds, which can impart red, yellow, or brown hues. Zinc and calcium do not significantly affect the coloration of these rocks.

The exosphere is the outermost layer of Earth's atmosphere and interacts with the magnetosphere at altitudes around 10,000 km. The magnetosphere is the region dominated by Earth's magnetic field, which extends far into space and influences charged particles in the exosphere.

The stratosphere is the atmospheric layer that extends from the top of the troposphere up to the bottom of the mesosphere. It lies above the troposphere and below the mesosphere, making option C correct.

The stratosphere contains the ozone layer, which absorbs most of the Sun's harmful ultraviolet (UV) radiation, protecting life on Earth. Infrared radiation and radio waves are not primarily absorbed in the stratosphere, and the ozone layer is part of the stratosphere, not something it absorbs.

Asteroids are primarily composed of rock, metal, ice, and dust. While many asteroids are mainly rock and metal, some also contain significant amounts of ice and dust, especially those farther from the Sun. Therefore, option A is the most accurate and complete answer.

The atmosphere is held in place by the gravity of the planetary body, which pulls the atmospheric gases toward the surface, preventing them from drifting into space.

The thermosphere typically extends from about 85 km altitude up to the base of the exosphere, which starts around 690 km. This matches option C, making it the correct answer.

The troposphere is thickest at the equator, reaching about 17 km, and thinnest at the poles, around 7 km, due to temperature differences affecting atmospheric expansion.

The stratosphere extends approximately from 17 km to 50 km above the Earth's surface. Among the given options, 17 km to 35 km is the closest and most accurate range for the lower to mid-stratosphere altitude.

The outermost layer of the Earth is called the crust. It is the thin, solid surface layer on which we live, distinct from the underlying mantle and core.

Oxygen is the most abundant element in the Earth's crust, making up about 46% by weight, primarily combined with other elements such as silicon and aluminum.

Igneous rocks form from the cooling and solidification of molten material (magma or lava) within or on the Earth's surface. This distinguishes them from sedimentary rocks, which form from sediment deposition, and metamorphic rocks, which form from existing rocks under heat and pressure.

Approximately 71% of the Earth's surface is covered by water, primarily oceans, seas, and other bodies of water. This is a well-established scientific fact.

Radium is a rare and radioactive element that is not abundant in the Earth's crust, unlike silicon, aluminum, and carbon which are common elements found in significant amounts.

The Earth's position in its orbit when it is farthest from the Sun is called Aphelion, which occurs around early July and coincides with the northern hemisphere's summer. This is why option A is correct.

Oxygen makes up about 50% of the Earth's crust by weight, and it is also a major component of the Earth's waters and atmosphere, making it the most abundant element in these combined components.

Sedimentary rocks are typically porous because they are formed by the accumulation of sediments, which often leave spaces or pores between grains. This porosity distinguishes them from many igneous or metamorphic rocks.

The Mariana Trench is the deepest known part of the Earth's oceans, reaching depths of about 11,000 meters (36,000 feet). It is more specific and accurate than the general term 'Trench'.

A seismograph is an instrument designed to record earthquake waves, and the magnitude of these waves is measured on the Richter scale, which quantifies the size of earthquakes.

Most of the ozone in Earth's atmosphere is concentrated in the stratosphere, specifically in the ozone layer, which absorbs and scatters ultraviolet solar radiation.

Most major tsunamis are generated by shallow-focus earthquakes with hypocenters less than 30 km deep because shallow earthquakes displace the seafloor more effectively, triggering large water waves.

The 2005 Pakistan earthquake, also known as the Kashmir earthquake, had a magnitude of 7.6 on the Richter scale, making option B the correct answer.

The term 'Cryosphere' refers to all the frozen water on Earth, including glaciers, ice caps, sea ice, and permafrost. This distinguishes it from the Hydrosphere (all water), Biosphere (all life), and Frigid Zone (a climatic region).