what percent is Cenozoic, Mesozoic, Paleozoic, and Precambrian of the Earth?
83780
pre-cambrian: 88%\n\npaleozoic: 7%\n\nMesozoic: 4%\n\nCenozoic: 1%
71321
Earth is composed of five main divisions or layers:\natmosphere, crust, mantle, outer core, and inner core.\n\nAstronomer: n. a scientist who specializes in astronomy, or the study of space.\n\nCrust: n. outer most layer of rock on Earth; the portion of Earth's surface with which we are most familiar; it is hard and brittle.\n\nMantle: n. the layer of the earth located below the crust, plastic in character and composed primarily of Fe and Mg.\n\nOuter core: n. the layer of the earth between the mantle and the inner core; theorized as liquid and comprised primarily of molten metal, mostly nickel.\n\nInner core: n. solid, inner-most portion of Earth.
339407
Here you go...\n\nGRAVITY:\n\nEarth - 100%\nMoon - 16%\nMercury - 37%\nVenus - 88%\nMars - 38%\nJupiter - 264%\nSaturn - 115%\nUranus - 93%\nPluto - 6%\nSun - 2790%
115408
3 main types: igneous, sedimentary, and metamorphic
530611
The Precambrian is more of an eon than an era.  The Precambrian period refers to everything that occurred before about 600 million years ago.  Since the Earth is about 4.6 billion years ago, that means the Precambrian was 4 billion years long.\n\nIn terms of geological events in the Precambrian, everything from the formation of the planet, the hypothesized impact that tore off the chunk of rock that would become our moon, the cooling of the molten Earth and formation of the continental plates, the condensation of water and formation of the oceans, the abiogenesis of life, the formation of single-celled organisms, the development of photosynthesis, and the subsequent atmospheric pollution that created our oxygen atmosphere, even the first multi-cellular life all occured in the Precambrian Eon.\n\nThe next period, from 600 million years ago on, is known as the Phanerozoic Eon.  It is split up into the Paleozoic, Mesozoic, and Cenozoic.\n\nThe Paleozoic was the longest period, from 600 million years ago to about 240 million years ago.  It was during this time that every living Phylum of multicellular animal evolved.  At first the seas were the only place where life existed, dominated by things like trilobites, crinoids and ammonites.  Fishes evolved in this period, and about mid-way through the very first land plants started to take root on the continents.  Insects soon followed, and then amphibians, which evolved into reptiles by the end of the period.  The Paleozoic ended with the largest mass extinction the Earth has yet seen, at the end of the Permian.  More than 90% of all species on Earth at the time went extinct.\n\nFollowing the Paleozoic was the Mesozoic.  Sometimes called the Age of Reptiles, the Mesozoic is split into three periods, the Triassic, Jurassic, and Cretaceous, and lasted until about 65 million years ago.  It was during this time that dinosaurs evolved, and became the dominant life on the planet.  There were other notable reptile groups as well, such as pterosaurs, plesiosaurs, icthyosaurs and mosasaurs, and groups such as the mammals and birds also evolved during this period.  Flowering plants also made their first appearance near the end of this period.\n\nFollowing another mass extinction at the end of the Cretaceous came the Cenozoic Era, also known as the Age of Mammals.  Adaptive radiation after the dinosaurs went extinct took the mammals from small, scurrying possum and shrew-like things into the wide array of hippos, horses, cats, dogs, bears, indricotheres, elephants, bats, monkeys and brontotheres of this age.  Partway through the Era, in the Oligocene, grasses evolved and changed much of the landscape of the planet as open prairie became a dominant ecozone.  This is the era we still live in today, our modern Holocene period is the latest section of the Cenozoic.
993258
The Earth was formed around 4.57 billion (4.57×109)[1] years ago
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8.7 percent of the Earth's total surface area, or \n29.8 percent of its land area, and it contains more than \n60 percent of the world's human population.
840716
Pre-Cambrian life was mostly soft-bodied -- there were very few if any creatures with bones, skeletons, or hard shells, so there were very few fossils left.\n\nBesides, it was a long, long time ago -- and geological activity on the earth (volcanic action, subduction of continental plates, erosion, etc.) have wiped out a lof of what was the surface of the earth then. :)
671187
The generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%). This value is derived from several different lines of evidence.\n\nUnfortunately, the age cannot be computed directly from material that is solely from the Earth. There is evidence that energy from the Earth's accumulation caused the surface to be molten. Further, the processes of erosion and crustal recycling have apparently destroyed all of the earliest surface.\n\nThe oldest rocks which have been found so far (on the Earth) date to about 3.8 to 3.9 billion years ago (by several radiometric dating methods). Some of these rocks are sedimentary, and include minerals which are themselves as old as 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on North America, Greenland, Australia, Africa, and Asia.\n\nWhile these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it). This lower limit is at least concordant with the independently derived figure of 4.55 billion years for the Earth's actual age.
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Geology is an earth science and is the study of rocks and minerals.
664993
75% of the earth...u do the rest of the calculation.
18396
You are looking for the Cnidaria corals I believe. In the early Paleozoic (cambrian to silurian) they diversified into tabulate corals, rugose corals, and heliolitid corals. All these forms were wiped out at the end of the Permian Period, in a mass extinction event that claimed something like 95% of all marine invertebrate species.\n\nDescriptions of these types of corals are linked in this page:\nhttp://www.ucmp.berkeley.edu/cnidaria/cnidariafr.html\n\n\nTHis page may also be a big help to you:\nhttp://www.paleoportal.org/fossil_gallery/taxon.php?taxon_id=55
692520
4.5 billion years. \n\nCheck with the US Geological Survey for a great timeline and all the data to back it up, based on radioisotopes of minerals found in rocks.
752370
Cambrian 540-500 MYO, Ordovician 505-438 MYO, Silurian 438-408 MYO, Devonian 408-360 MYO,(age of fishes), Caboniferous 360-280 MYO, Permian280-248 MYO (age of amphibians), Triassic 248-208 MYO, Jurassic 208-146 MYO, Cretaceous 146-65 MYO, Tertiary 65-1.8 MYO, Theres a little way to remember these periods, my year 12 geology teacher taught it to me.  The first letter marks a period. Camels, Often, Sit, Down, Carefully, Perhaps, Their, Joints, Creek, Terribly. Then finally you have the age of man from 1.8 MYO to the present. This is known as the Quaternary period.\n\nThere are 3 eras, Paleozoic 540-248 MYO, Mezosoic 248-65 MYO (age of reptiles) Cenozoic 65 MYO -present (the age of mammals)
454213
I have disagree with the first answer as 35% of the earth is Iron. And while Aluminum is more abundent on the surface, nearly 80% of the core is iron. So I have to go with Iron.
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http://www.psigate.ac.uk/newsite/earth_timeline.html\nhttp://www.sdnhm.org/fieldguide/fossils/timeline.html\nhttp://www.talkorigins.org/origins/geo_timeline.html\nhttp://en.wikipedia.org/wiki/Geologic_timescale\n\nI hope these help.
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Silurian (440 to 410 million years ago)\n    * First land plants\n\n\nSource: \nFossils and the geological timescale\nhttp://en.wikipedia.org/wiki/Fossils_and_the_geological_timescale