Weight of the Earth

A measure of the proportion of all solids and liquids is a cube. cm chemically pure water, weighing, as we know, 1 oz. By adopting the density of water per unit, and knowing how many times heavier than its substance, we find its specific gravity. 1 cu. cm lime weighs 2.9 grams.: it 2,9 times heavier than 1 cu. cm of water, so they say, that the proportion of lime is 2,9; 1 cu. cm gold weighs 19.4 grams.: its share of 19.4. By challenging experiments were able to determine the proportion of the Earth: it is taken 5.5, which means that the globe in 51 / 2 times heavier than the chemically pure water of the same volume. But among the rocks forming the crust, no one has such a large proportion. If, on the other hand, we define the share of major rock, taking an important part in the composition of the Earth, it would appear that they are harder than the deeper lying: for example, the proportion of sedimentary rocks on average 2.6 and granite - 2 , 7, basalt is 3, and olivine rocks 3,3 - 3,5. We can conclude that inside the Earth below the olivine field are the masses of higher specific gravity, thanks to them, the density of Earth, reaching 5.5 in general. So have a specific gravity of only heavy metals, and because nearly all geologists believe that Earth's core and consists of them, because these metals are amongst the most common is iron, it is highly likely that the metal takes important part in forming the interior of the Earth . Rarity of native iron in the Earth's surface is explained on the one hand, the fact that the eruption of large depths rarely reach the surface, on the other hand, iron is poorly stored in humid air and easily oxidized.