In each pair of isotopes shown, indicate which one you would expect to be radioactive. (a) 20 Ne 10 or 17 Ne 10 (b) 40 Ca 20 or 45 Ca 20 neon−20 neon−17 calcium−45 calcium−40 (c) 95 Mo 42 or 92 Tc 43 (d) 195 Hg 80 or 196 Hg 80 technetium−92 molybdenum−95 mercury−196 mercury−195 (e) 209 Bi 83 or 242 Cm 96 bismuth−209 curium−242