Answer:
See whole explanation to understand
Explanation:
the reason why there is such a large jump from 2nd to 3rd ionization energy for calcium is because to remove the third electron, a larger amount of energy is required, since the shell is closer to the nucleus, and higher attraction exists between them. This is why the second ionization energy is 1125.4 and then the third IE is 4912.4 which is a very big difference. It's all about the elections and energy!!
I will have to go with carbon monoxide
The Great Oxidation Event (GOE), sometimes also called the Great Oxygenation Event, Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust,[2] or Oxygen Revolution, was a time period when the Earth's atmosphere and the shallow ocean first experienced a rise in oxygen, approximately 2.4 billion years ago (2.4 Ga) to 2.1–2.0 Ga during the Paleoproterozoic era.[3] Geological, isotopic, and chemical evidence suggests that biologically produced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere,[4] causing many existing species on Earth to die out.[5] The cyanobacteria producing the oxygen caused the event which enabled the subsequent development of multicellular forms.