Composition
Based on the abundance of chemical elements in the solar system, the theory of planetary formation, and other chemical constraints regarding the remainder of Earth's volume, the inner core is composed primarily of a nickel–iron alloy referred to as Nife: 'Ni' for nickel, and 'Fe' for ferrum or iron. Because the inner core is more dense (12.8 ~ 13.1)g⁄cm³ than pure iron or nickel, even under heavy pressures, it's believed that the remaining part of the core is composed of gold, platinum and other siderophile elements in quantity enough to coat Earth's surface for 0.45 m (1.5 feet). The relative abundance of precious metals and other heavy elements in respect to Earth's crust is explained with the theory of iron catastrophe, an event which occurred before the first eon during the accretion of early Earth.
Read more about this topic: Inner Core
Famous quotes containing the word composition:
“At painful times, when composition is impossible and reading is not enough, grammars and dictionaries are excellent for distraction.”
—Elizabeth Barrett Browning (1806–1861)
“Boswell, when he speaks of his Life of Johnson, calls it my magnum opus, but it may more properly be called his opera, for it is truly a composition founded on a true story, in which there is a hero with a number of subordinate characters, and an alternate succession of recitative and airs of various tone and effect, all however in delightful animation.”
—James Boswell (1740–1795)
“The naive notion that a mother naturally acquires the complex skills of childrearing simply because she has given birth now seems as absurd to me as enrolling in a nine-month class in composition and imagining that at the end of the course you are now prepared to begin writing War and Peace.”
—Mary Kay Blakely (20th century)