Regents Chemistry Test Preparation Practice

    Proton Neutron Electron

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    Base your answers to questions 14 on the information below and on your knowledge of chemistry.

    The atomic mass and natural abundance of the naturally occuring isotopes of hydrogen are shown in the table below.

    proton-neutron-electron fig: chem62019-exam_g12.png

    The isotope H-2, also called deuterium, is usually represented by the symbol “D.” Heavy water forms when deuterium reacts with oxygen, producing molecules of D2O.

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    Base your answers to questions 15 on the information below and on your knowledge of chemistry.

    One fission reaction for U-235 is represented by the balanced nuclear equation below.

    nuclear-reactions fig: chem82015-exam_g9.png

    Both radioisotopes produced by this fission reaction undergo beta decay. The half-life of Xe-140 is 13.6 seconds and the half-life of Sr-94 is 1.25 minutes.

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