Chemistry 17/1/19

  • Created by: Emma
  • Created on: 21-12-18 14:03

Describe the Earth’s early atmosphere

The Earth's early atmospher was made up of 95% of carbon dioxide, and 5% was made up of oxygen,nitrogen and hydrogen.

It began when volcanoes released C02, water vapour and other gases. The water vapour then caused oceans and the co2 was used by plants.

Define endothermic and exothermic reactions

Endothermic reactions take heat in eg. cold pack whereas exothermic let heat out into the environment eg. the


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