Uranium 235 Decays Into The Daughter Product ________.

Most important factor in the formation of fossils: Rapid burial

These rocks form directly from molten material (lava, magma) that cools down and becomes solid Igneous rock

These form when broken rock pieces are transported by wind or water, accumulate in low-lying areas, and become cemented together into a new type of roxk Sedimentary rocks

Most fossils are found in these rocks Sedimentary rocks

Although these rocks usually don't contain fossils (except in the case of ash falls), they're very important for paleontologists because we can readily determine their absolute ages Igneous rocks

Pioneered research on radioactivity, which provides the basis of absolute dating Marie Curie

Argued that Earth must be incredibly old, based on simple observations of erosion and deposition above tilted sedimentary sequences (uniformitarianism, Siccar Point and Unconformity) James Hutton

Argued that sediments are typically deposited in horizontal and continuous layers, with younger layers on top of older ones, and that fossils form when these sediments bury bones and then turn into sedimentary rocks (3 principals: original horizontality, lateral continuity, and superposition) Nicolas Steno

Realized that fossil species occur in a specific sequence, allowing rock layers to be correlated based on the fossils within them. (Faunal succession); things do become extinct George Cuvier

Is it impossible to determine the absolute ages of sedimentary rocks because none of the grains in these rocks contain radioactive elements? No; it is possible, the grains of rocks do contain radioactive elements

Can we determine the age of most dinosaur fossils through carbon dating, which relies on the radioactive decay of carbon-14? No; carbon-14's half life is not old enough. Uranium-235 : lead-207 is a good alternative for dating dinosaur fossils

Uranium-235 (U-235) decays into lead-207 (Pb-207). You find 1000 atoms of U-235 and 3000 atoms of Pb-207. How many atoms of these elements were in the original mineral? 4000 of U-235 and 0 of Pb-207

You find 1000 atoms of U-235 (parent) and 3000 atoms of Pb-207 (daughter) in a mineral. If the half life of U-235 is 700 million years, then how old is the mineral? If the mineral came from an igneous rock, then how old is the rock? The mineral is 1400 million years old, and the rock is the same age

You've just discovered a new radioactive element. At 1:00 PM I measure 10 grams of the element, but at 1:15 PM I measure only 1.25 grams of the element (with 8.75 grams of the daughter product). How long is each half life, in minutes? 5; divide ten by two, you get five, then by two again, you get 2.5, then by two again, and you finally get 1.25. This took 3 half lives. To find out how old each half life is, divide the time passed (15 minutes) by 3. The answer is 5.

T or F: there is somebody currently alive today that was born closer to George Washington taking the presidency than to today True

T or F: the ancient Egyptian civilization lasted longer than the Roman Empire, the Middle Ages, the European colonization of the americas, and U.S. history combined True

T or F: There is a recorded history for most of the time that humans have been behaviorally modern. False

T or F: T. Rex lived closer to today than to a time when Stegosaurus was still alive True

T or F: our solar system, which is a part of the Milky Way Galaxy, was formed at about the same time as the Milky Way itself False

The abbreviation Ma stands for: Mega anum- referring to millions of years ago

The Precambrian accounts for about ____ percent of Earth's history 88%

How old is the earliest solid evidence of life on the planet? 3500 Ma

T or F: The first multicellular animals appear before the first eukaryotes False

Vertebrates evolve jaws in the _______, then transition to land in the _________, and the earliest amniotes are known from the _______. Early Paleozoic; middle Paleozoic, late Paleozoic

The first dinosaurs are known from the ________, but don't dominate the planet until the __________. Middle Triassic; Jurassic

T or F: The first mammals are known from the early Cenozoic, which suggests that they didn't evolve until after most dinosaurs went extinct. False; the first mammals are known from the late Triassic. Birds and mammals however RADIATE in the Cenozoic.

T or F: Homo Sapiens are a very young species (in geological terms), yet every single person alive today is the result of an unbroken line of successful reproductive events that stretches back at least 3.5 billion years! True