8.Tides on Earth are caused primarily by A.the moons gravitational force. C.Earths landscape. B.the suns gravitational force. D.Jupiters gravitational force.
9._____ is the only planet in the solar system known to sustain life. A.Uranus C.Earth B.Mercury D.Pluto
10.Earths atmosphere protects it from A.high-energy solar particles. C.space debris. B.ultraviolet radiation. D.All of the above
11.Astronomers believe _____ was originally a part of Earth. A.the sun C.Jupiter B.the moon D.Mars
12.According the current theory, the moon was formed A.together with Earth. C.from a portion of Earth. B.separately from Earth. D.from leftover matter.
13.The moons surface is covered with A.craters. C.ice. B.oceans. D.an atmosphere.
14.When the moon is full, the _____ is between the _____ and the _____. A.moon, sun, Earth C.Earth, moon, sun B.sun, Earth, moon D.moon, sun, Mercury
15.The age of our solar system is approximately A.2,000 years old. C.4.6 billion years old. B.46 billion years old. D.13.7 billion years old.
16.A rock that strikes the Earth is called a A.meteor. C.meteoroid. B.meteorite. D.All of the above
17.During a solar eclipse A.the moon blocks out the sun. C.the moon blocks out Earth. B.the sun blocks out the moon. D.Earth blocks out the sun.
18.During a lunar eclipse A.the moon blocks out the sun. C.the moon blocks out Earth. B.the sun blocks out the moon. D.Earth blocks out the sun.
19._____ allow Earth to sustain life. A.Liquid water and an oxygen-rich atmosphere B.Animals and plants C.The moons craters and maria D.Ice and a methane-rich atmosphere
20.The principle that uses the position to determine the relative age of rock layers is called the A.law of cross cutting C.law of superposition B.Newtons Law D.law of horizontality
21.Half lives are used to determine the _____________ age of rocks. A.relative C.youngest B.absolute D.oldest
22.The principle that states that a layer of rock that cuts across other layers of rock is younger than the rock it cuts through is called the A.law of cross cutting C.law of superposition B.Newtons Law D.law of horizontality
23. A wooden boat is found buried in the ocean. Scientists believe that timbers making up the boat had 10mg of carbon- 14 in them when alive. They now have 2.5mg of carbon-14. How old is the boat if the half life of carbon-14 is 5715 years?
24. Potassium-40 has a half-life of 1.3 billion years. If I have a sample which weighs 80 grams, how long will it take for the sample to have only 5 grams of potassium-40 left?
25. The half-life of thorium-230 is 2.25 million years. I have a sample which originally contained 20kg of thorium-230, but now only contains 5 kg of thorium How old is my sample?