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24 week assessment
24 week assessment Science-Gwen Gould
Question | Answer |
---|---|
what is the scentifically accepted age of the earth | 4.6 billion years |
What is uniformitarism? Who identified the principle? | Uniformitarianism is the principle that geologic processes that occurred in the past can be explained by current geologic processes. It was identified by James Hutton. |
* What does the Law of Superposition state? | A sedimentary rock layer is older than the layers above it and younger than the layers below. |
* What does the Law of Cross-cutting Relationships state? | A fault or igneous intrusion is always younger than the rock layers it cuts through. |
* Radiometric Dating—what is a half-life? What do the terms “parent and daughter isotopes” mean? | The half-life is the time it takes for half of the radioactive parent isotope to decay into the stable daughter isotope. |
* What is Carbon-14 dating used for? | A method of dating fossils (wood, shells, bones, etc.) that are less than 70,000 years old. |
* What is an index fossil? | A fossil that occurs in a rock layer of a particular geologic age—lived for a short time, was very common and world-wide. |
* Why are there few fossils found in Precambrian rocks? | There were not a lot of life forms (mostly bacteria), no hard parts to fossilize, and many of the rocks from that time period have been deformed (melted, eroded, faulted). |
* What was the major cause of the Permian extinction? | Many of the inland seas dried up. Many marine invertebrates went extinct. |
* What is the major cause of the Cretaceous extinction? | Asteroid strike |
* What marks the boundary between the Pleistocene and the Holocene epochs? | End of the last ice age |
* Identify and define the layers of the Sun’s atmosphere: | The photosphere. The chromosphere . The corona |
* What causes them? Where are they usually seen? | Caused by the interaction of the solar wind and Earth’s magnetosphere. Bright bands of light in the sky mostly seen at higher latitudes. |
* What is the difference between a solar flare and a coronal mass ejection? | A solar flare is an explosive release of energy that comes from the Sun and that is associated with magnetic disturbances on the Sun’s surface. A CME is made up of coronal gas that is thrown into space from the Sun. |
* How does nuclear fusion create energy in the Sun’s core? | On the Sun hydrogen is fused into helium. |
* What is a sunspot? What is the average length of the sunspot cycle? | A sunspot is a dark area of the photosphere of the Sun that is cooler than the surrounding areas, and that has a strong magnetic field. The average sunspot cycle is 11 years. |
* What is cosmology? | The scientific study of the Universe |
* What is the scientifically accepted age of the universe? | 14 billion years old |
* Explain the Big Bang Theory | The theory that the universe began as a small point of matter that suddenly and rapidly began expanding outward. |
* What is the cosmic background radiation? | Low levels of energy that are distributed evenly throughout the universe. This is evidence that supports the Big Bang Theory. |
* What galaxy do we live in? | Milky Way galaxy |