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(24-Week Assessment

Earth, History and Astronomy study guide

QuestionAnswer
What is the scientifically accepted age of the Earth? 4.6 billion years old
What does the Law of Superposition state? Undeformed sedimentary rock layer is older than the layers above, younger rock layers is below it
What does the Law of Cross-cutting Relationships state? Fault or igneous intrusion is always younger than the rock layers it cuts through
Radiometric Dating--What is a half -life? The time it takes half the mass of a given amount of a radioactive isotope to decay into it's daughter isotope
Radiometric Dating--What do the terms "Parent and daughter isotopes" mean? Concentrations of the original radioactive isotope. Newly formed isotope is the daughter isotope.
What is Carbon-14 dating used for? Determine the age of wood, bones, shells, and other organic remains that are less than 700,000 years old.
What is an index fossil? Fossils that occur in short period of time
Why are there few fossils found in Precambrian rocks? No hard tissue
What was the major cause of the Permian Extinction? Cooling of Earth
What is the major cause of the Cretaceous extinction? Asteroid
What marks the boundary between the Pleistocene and the Holocene epochs? Human domination
What causes auroras? Solar winds colliding with the magnetosphere
What causes a geomagnetic storm? Particles from the sun
How does nuclear fusion create energy in the Sun's core? Combining hydrogen then release energy
What is the average length of the sunspot cycle? 11 years
What is the scientifically accepted age of the Universe? 14.772 billion years
Explain the Big Bang Theory Explosion forced matter outwards
What is the cosmic background radiation? Electromagnetic radiation from big bang
What Galaxy do we live in? Milky Way
Fossils of organisms presence life foot prints are called_______ fossils Trace
Name 2 reasons why there are not many fossils from the Pre-Cambrian time?(Two Parts) No hard tissue and Metamorphic rock
Our currents epoch, the Holocene was started by what? The first Ice Age
Cooling spots in the atmosphere of the sun are called what? Sunspots
How long is a sun spot cycle? 11 years
What are disturbances from the outer layer of the sun's atmosphere which can interrupt radio signal on earth? Electromagnetic radiation from the big bang
What is left over evidence of the big bang theory? Cosmic background(Electromagnetic radiation)
What is the fuel of the sun? Hydrogen
What is the waste of the sun's nuclear fusion? Helium
Colored light created by solar winds colliding with the magnetosphere are called what? Aroura
Created by: Randy Nguyen🐢