All flashcards topics

Earth & Atmospheric ScienceEdexcel GCSE Chemistry: Flashcards

Card 1 of 130 of 13 known

Question

What produced the Earth's early atmosphere?

Tap or press Space to reveal

Tap card or press Space to flip

See all 13 cards
What produced the Earth's early atmosphere?
Volcanic activity (volcanoes releasing gases).
What three things did the early atmosphere mostly contain?
A large amount of carbon dioxide, water vapour, and little or no oxygen.
How did the oceans form?
Water vapour condensed as the Earth cooled.
How did carbon dioxide levels in the atmosphere fall after the oceans formed?
Carbon dioxide dissolved into the oceans, and was later locked into sedimentary rocks and fossil fuels.
What process released oxygen into the atmosphere?
Photosynthesis by early plants and algae, which used carbon dioxide and released oxygen.
What is the chemical test for oxygen?
Insert a glowing splint into the gas — it relights if oxygen is present.
What is the approximate composition of today's atmosphere?
About 80% nitrogen, 20% oxygen, with small amounts of carbon dioxide, argon and other gases.
Name three greenhouse gases.
Carbon dioxide, methane and water vapour.
Explain the greenhouse effect.
Greenhouse gases absorb heat radiated from the Earth's surface and re-release it in all directions, warming the Earth.
What two human activities increase greenhouse gas levels?
Burning fossil fuels (releases CO2) and livestock farming (releases methane).
What correlation is used as evidence for human-caused climate change?
A correlation between rising atmospheric CO2, increasing fossil fuel consumption and rising global temperature.
Name two uncertainties in climate change evidence.
Measurements are taken at different locations (may not be representative), and historical data (e.g. from ice cores) has some inaccuracy.
What must be considered when evaluating ways to mitigate climate change?
Scale, risk and environmental implications.