When did photosynthetic algae begin producing oxygen?
About 2.7 billion years ago.
AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Foundation · 5.9.1.3
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When did photosynthetic algae begin producing oxygen?
About 2.7 billion years ago.
When did oxygen begin appearing in the atmosphere relative to oxygen production by photosynthetic algae?
Soon after the algae began producing oxygen.
What happened to plants and atmospheric oxygen over the next billion years after oxygen began appearing in the atmosphere?
Plants evolved, and the percentage of atmospheric oxygen gradually increased.
What did the gradual build-up of atmospheric oxygen eventually allow to evolve?
Animals.
What was the original source of oxygen in Earth’s atmosphere?
Photosynthetic organisms produced it through photosynthesis.
What is the overall word equation for photosynthesis, including the energy input?
Carbon dioxide + water — using light energy → glucose + oxygen.
What is the balanced symbolic equation for photosynthesis?
In the balanced photosynthesis equation, how many carbon, hydrogen and oxygen atoms are on each side?
6 carbon, 12 hydrogen and 18 oxygen atoms.
What does a coefficient in a chemical equation multiply?
The entire formula following it; it does not change the formula of an individual molecule.