The Earth's early atmosphere
The Earth's early atmosphere
The young Earth was extremely volcanically active. Eruptions released gases from inside the Earth for hundreds of millions of years, and these gases collected around the planet to form the first atmosphere.
Step-by-step lessons on Edexcel GCSE Chemistry 9.2 Earth and atmospheric science, covering 9.2.1 The Earth's early atmosphere, 9.2.2 How the atmosphere evolved, 9.2.3 Chemical test for oxygen, and 9.2.4 The greenhouse effect and climate change. Each one builds up to exam-style questions. Nail the core quantitative topics — moles, balancing equations and calculations — early on, since they underpin higher-tier questions across every paper and topic.