Chemical properties | Modern conditions | Early life conditions | |||||||
---|---|---|---|---|---|---|---|---|---|
Cation | Hydration number | Ionic radius (Å) | pK a | Hardness (η c) | Oceans (mM) | Cells (mM) | Archaean ocean (%) | Hydrothermal vents (mM) | Affinity for montmorillonite clay ( k a/ k Cd) |
Mg2+ | 6 | 0.72 | 11.42 | 47.59 | 50 | 30 | 24 | 51 | 0.9 |
Ca2+ | 8 | 1.12 | 12.70 | 19.52 | 10 | 1 | 29 | 232 | 5.8 |