Forming the modern atmosphere
Compared to the Earth’s early The layers of gases that surround the Earth. The important gases in the atmosphere are nitrogen, oxygen and carbon dioxide., the modern atmosphere is oxygen-rich. It contains:
- less water vapour
- less carbon dioxide
- more oxygen
Question
Name the most abundant gas in the modern atmosphere.
Nitrogen.
Water vapour
The Earth cooled after it formed. When it became cool enough, water vapour in the atmosphere Turned from a gas or vapour into a liquid, usually as a result of cooling.. It fell as rain, creating the oceans.
Carbon dioxide
Carbon dioxide is a very Able to dissolve in solvent. For example, sugar is soluble in water because it dissolves to form sugar solution. gas. It When a substance breaks up and mixes completely with a solvent to produce a solution. readily in water. As the oceans formed, carbon dioxide dissolved and the amount of it in the atmosphere decreased.
Oxygen
Plants make their own food by A chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy. Oxygen is produced as a by-product of photosynthesis. Algae subsumed within plants and some bacteria are also photosynthetic.. In this process, carbon dioxide from the atmosphere reacts with water. Glucose is produced, with oxygen as a Something that is produced as a waste product..
Photosynthesis by Something that is in its earliest and simplest stage of development. plants and A group of organisms that photosynthesise but lack the complex range of cell types and organs found in land plants. Most algae are aquatic. All have chloroplasts. caused the removal of carbon dioxide from the air, and the release of oxygen. This had two effects:
- the amount of carbon dioxide decreased further
- the amount of oxygen in the atmosphere gradually increased
Question
Describe two reasons why the amount of carbon dioxide in the atmosphere decreased over time.
Carbon dioxide dissolved in the oceans, and primitive plants used it for photosynthesis.
