21. Archaeologists use the half-life of _____ to date organic materials. A.carbon-12C.carbon-14B.uranium-235D.uranium-238
32. Radioactive materials have unstable A.electrons.C.protons.B.nuclei.D.neutrons.
43. The process of nuclear change in an atom of radioactive material is called A.radioactive decay.C.nuclear mass.B.isotopes.D.radon.
54. Nuclei with too many or too few neutrons are A.never found.C.unnatural.B.unstable.D.stable.
65. In radioactive decay, with each half-life, half the remaining sample decays to form another A.nucleus.C.life-form.B.element.D.proton.
76. All planets in the solar system revolve around A.the sun.C.Jupiter.B.Earth.D.Mars.
87. The moon orbitsA.Earth.C.Saturn.B.the sun.D.Mercury.
98. Tides on Earth are caused primarily by A.the moon’s gravitational force.C.Earth’s landscape.B.the sun’s gravitational force.D.Jupiter’s gravitational force.
109. _____ is the only planet in the solar system known to sustain life. A.UranusC.EarthB.MercuryD.Pluto
1110.Earth’s atmosphere protects it from A.high-energy solar particles.C.space debris.B.ultraviolet radiation.D.All of the above
1211.Astronomers believe _____ was originally a part of Earth. A.the sunC.JupiterB.the moonD.Mars
1312.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.
1413.The moon’s surface is covered with A.craters.C.ice.B.oceans.D.an atmosphere.
1514.When the moon is full, the _____ is between the _____ and the _____. A.moon, sun, EarthC.Earth, moon, sunB.sun, Earth, moonD.moon, sun, Mercury
1615.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.
1716.A rock that strikes the Earth is called a A.meteor.C.meteoroid.B.meteorite.D.All of the above
1817.During a solar eclipseA.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.
1918.During a lunar eclipseA.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.
2019._____ allow Earth to sustain life. A.Liquid water and an oxygen-rich atmosphereB.Animals and plantsC.The moon’s craters and mariaD.Ice and a methane-rich atmosphere
2120.The principle that uses the position to determine the relative age of rock layers is called the A.law of cross cuttingC.law of superpositionB.Newton’s LawD.law of horizontality
2221.Half lives are used to determine the _____________ age of rocks. A.relativeC.youngestB.absoluteD.oldest
2322.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 theA.law of cross cuttingC.law of superpositionB.Newton’s LawD.law of horizontality
2423. A wooden boat is found buried in the ocean 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?
2524. Potassium-40 has a half-life of 1. 3 billion 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?
2625. The half-life of thorium-230 is 2. 25 million years 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?