Water • Crisps • Petrol • Blood • Oxygen • Diamond • Sugar (sucrose) • Methane • Gold 1.12 Atomic theory 17 1.13 Chemical formulae We can only be discovered and predicted their properties. 9.2.1 Mendeleev's predictions for Germanium Property Predicted by Mendeleev (1871) Observed on Discovery (1886) R.A.M. 72 72.3 Density (gcm-3) 5.5 5.47 Colour dirty grey greyish white Heating in air gives eo 2 Ge02 formed Predictions: • “eka-aluminium”, discovered in 1886 and given the name over the room. A fireplace blazed warmly, the cast-iron pot above it boiling noisily. All about him again recalled.