Question 19 (4 points) Listen A Physicist is studying a newly discovered radioactive isotope. She begins her experiment with a 4 x 10-8 kg sample of the isotope, and over the course of several hours, the sample emits several gamma rays. After the experiment, the sample now weighs 3 x 10-8 kg. Which of the following describes what happened? O The isotope gamma decayed, turning some of its energy into the energy of the gamma rays. O The isotope gamma decayed, turning some of its energy into the mass of the gamma rays. O The isotope gamma decayed, turning some of its mass into the mass of the gamma rays. O The isotope gamma decayed, turning some of its mass into the energy of the gamma rays.Question 20 (4 points) Listen One of the first artificial nuclear reactions was produced in 1932 when a Lithium-7 nucleus was bombarded by a proton, causing it to decay and emit an alpha particle. Write the equation for this reaction. He + He OLi+ H - He+ He Olli + H - ,He + He (Lithium-7 + proton --> alpha + Helium-4Question 21 (4 points) A bubblechamber is a device used by phakists to arabce the motion and der actorbliss d' substank paticks. Whenthepatickes brand through the charts, they kwe treks of bibbis behind than which shows the pails they take The chamber babo placedinsidea wry strong magdic fidd so that the scientists cantd the difference between changed and neutral dots. Below 6 a dagrand two different botypes that was placedin a bubble chamber. Based on the pails made by the partides they grit ted four dilfaert phaidats triedto kertily which type of decay eachis dope paformed + Scientist A: Isotope A experienced gamma decay because the partide traveled in a broad straight line and was only slightly affected by the magnetic field. This shows that the particle must be charged and have a large mass. botope B experienced beta decay because the particle emitted was very strongly affected by the magnetic field causing it to spiral. This shows that the particle must be charged and is very light." Scientist B: Isotope A experienced beta decay because the particle traveled in a broad straight line and was only slightly affected by the magnetic field This shows that the particle must have a charge and is very light. Isotope B experienced alpha decay because the particle emitted was very strongly affected by the magnetic field causing it to spiral. This shows that the particle must be charged and have a large mass ." Scientist C:"Isotope A experienced alpha decay because the particle traveled in a broad straight line and was only slightly affected by the magnetic field This shows that the particle must be charged and have a large mass. botope B experienced beta decay because the particle emitted was very strongly affected by the magnetic field causing it to spiral. This shows that the partide must be charged and is very light." Scientist D: "Isotope A experienced gamma decay because the particle traveled in a broad straight line and was only slightly affected by the magnetic field. This shows that the particle must have a charge and is very light. Isotope B experienced alpha decay because the particle emitted was very strongly affected by the magnetic field causing it to spiral. This shows that the partide must be charged and have a large mass ." Which sd andist comectly identified the the decay of each Isotope with the propa mason ling? Scientist A Scientist B Scientist C Scientist DQuestion 22 (4 points) Listen Periodic Table of Elements 17 Er ail sclock From the list below, choose the atoms that ONLY have radioactive isotopes. Bismuth Nitrogen Lead O Gold Curium Uranium Oxygen Carbon Radium HydrogenQuestion 23 (4 points) () Listen A nucleus of Po-218 (atomic# 84) undergoes alpha decay. Which of the following equation correctly shows this reaction. O -Po = APb + ; He 118 PO 218 84- O 84 213 Po - 216 *Hg + ;He O 218 " Po -> 214 "pb + HeQuestion 24 (4 points) () Listen When a radioactive nucleus undergoes alpha decay, its mass number O decreases by four (4) O increases by four (4) O remains constant decreases by two (2)Question 25 (4 points) ) Listen Check all that occur when a radioactive nucleus ejects an alpha particle. The atomic number decreases. The mass number decreases. The remaining nucleus is more negative. The remaining nucleus is more positive. O