The question asks to identify the gas that forms the largest proportion of Earth's atmosphere by volume. This requires knowledge of the approximate composition of the Earth's atmosphere.
Correct Option: B) Nitrogen
Nitrogen gas (\(\text{N}_2\)) accounts for approximately 78% of the Earth's atmosphere by volume, making it the most abundant gas.
The question asks about the concentration of the Earth's atmospheric mass near the surface. This is a factual question related to the structure and composition of the atmosphere, specifically how air density changes with altitude.
Correct Option: A) 99 per cent. This is a well-established fact in atmospheric science. The gravitational pull causes air molecules to be concentrated closer to the Earth's surface, leading to a rapid decrease in density with increasing altitude. Consequently, the vast majority of the atmosphere's mass is found in its lowest layers.
The question asks about the height at which oxygen becomes almost negligible in the Earth's atmosphere. This requires knowledge of the composition and structure of the atmosphere, specifically the distribution of gases with altitude.
C) 120 km is the approximate height at which oxygen becomes almost negligible in quantity in the Earth's atmosphere. Above this altitude, the atmosphere is extremely thin, and the composition changes, with lighter gases like hydrogen and helium becoming more dominant.
The question asks about the vertical distribution of carbon dioxide and water vapour in the Earth's atmosphere. To answer this, we need to recall the composition and structure of the atmosphere, specifically how the concentration of different gases changes with altitude.
Correct Option: A) 90 km. Carbon dioxide and water vapour, while most concentrated in the lower atmosphere, can be found in trace amounts up to about 90 km, especially water vapour which forms noctilucent clouds in the mesosphere.
The question describes a property central to the greenhouse effect. We need to identify the gas that allows shortwave solar radiation to pass through but absorbs longwave terrestrial radiation, thereby trapping heat in the atmosphere.
C) Carbon dioxide — Carbon dioxide is a potent greenhouse gas. It is largely transparent to incoming shortwave solar radiation, allowing it to pass through to the Earth's surface. However, it is highly opaque to outgoing longwave terrestrial radiation, meaning it efficiently absorbs this heat energy, contributing significantly to the greenhouse effect and global warming.
The question asks to identify the atmospheric phenomenon primarily caused by carbon dioxide. We need to understand the role of carbon dioxide in the Earth's atmosphere and its impact on various atmospheric processes.
Correct Option: C) Green house effect
Carbon dioxide is a primary greenhouse gas. It absorbs infrared radiation emitted from the Earth's surface, trapping heat in the atmosphere and contributing significantly to the greenhouse effect, which warms the planet.