Most Periodic Tables Indicate the Elements for Which All Isotopes

question 17

Multiple Choice

Most periodic tables indicate the elements for which all isotopes are radioactive.Which pair of elements with atomic number less than 83 have only radioactive isotopes?

• A)Pb and At
• B)Tc and Cd
• C)K and Pm
• D)Tc and Pm
• E)C and K

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