4 ms·

Earth isn't even really a "rock", it's mostly a ball of iron. It's a ball of iron covered with rocks (i.e. metal oxides) cover with water (i.e. hydrogen oxide)

• zamadatix 2y ago
  I don't buy it. Even allowing counting iron as separate from what rocks can be composed of (and using mass instead of volume) you still have 30.1%+15.1%=45.2% of the Earth as oxygen and silicon (which are most certainly part of what makes a rock) at which point you've already disproved the claim Earth is more a ball of iron than a ball of rock. A ball of iron covered with a ball of rocks is a more fair statement though, and I'd agree with that. It's just that center ball isn't most of what makes up the Earth (by any measure).
  • ars 2y ago
    https://s3-us-west-2.amazonaws.com/courses-images-archive-read-only/wp-content/uploads/sites/567/2015/09/21153205/800px-Earth-crust-cutaway-english.svg_.png https://s3-us-west-2.amazonaws.com/courses-images-archive-re... Everything up to and including the mantle is either iron or has a lot of iron. But to your point the mantle also has a lot of silica. So I guess it depends on your definition of "mostly".
    • dredmorbius 2y ago
      Mass is the defining characteristic of a quantity of matter. Given that much of the iron is under far higher compression than the outer layers of silicate rock, this also advantages iron. By mass, iron (32.1%) is still a minority constituent of the Earth. <https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements#Earth https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elem...>