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ASTRO 7N Exam 3 includes accurate and verified questions covering fundamental astronomy concepts such as the solar system, phases of the Moon, planetary motion, gravity, light and telescopes, and the historical development of astronomical models. Designed for students in introductory astronomy courses such as those offered at Penn State.
The sun is composed of mostly: - ANSWER-hydrogen (73%)
and helium (25%)
How does the sun stay stable? - ANSWER-there is a balance of gravity that pushes inward, and gas pressure that pushes outward
What drives the gas pressure in the sun that pushes the sun outward? - ANSWER-Process called nuclear fusion that occurs at 15MM degrees Kelvin that produces energy
What is the conversion of the suns diameter to the earths? - ANSWER-One sun diameter is 109 earth diameters.
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What is the conversion of mass from the sun to earth? - ANSWER-One sun mass is 333,000 earth masses
Luminosity - ANSWER-the true brightness of an object
How bright is the sun? - ANSWER-4 x 10^24 100-watt bulbs
99.9% of ALL THE MASS in the solar system is in the - ANSWER-Sun ALONE
How long has the sun been shining? - ANSWER-4.50 bn years and it will CONTINUE to shine for another 5.50 bn years
Sunspots - ANSWER-slightly cooler areas on the surface of the sun that - due to magnetic activity - prevent hot material from rising in that region.
How long is a sunspot cycle - ANSWER-11 years
Nuclear fusion - ANSWER-the energy source of stars (the force that pushes against gravity to keep the sun in place)
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Under nuclear fusion, what happens? - ANSWER-4 protons combine to make helium and release energy through the subsequent gamma rays
The end result of what is made in nuclear fusion is called: -
ANSWER-the Proton-Proton Chain
What is the first step of the proton-proton chain - ANSWER-two protons collide at a high speed and stick together. One of these then changes to a neutron to form a deuterium nucleus and then releases energy
What is step two of the proton proton chain - ANSWER-The deuterium nucleus (one proton and one neutron) then collides with another proton and makes a helium 3 nucleus. During this step, some more energy is released
What happens during step three of the proton-proton chain? - ANSWER-the helium 3 nuclei which both contain two protons and one neutron then collide together to form the helium 4 nuclei
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