Competitive Exams: Chemistry MCQs (Practice-Test 27 of 31)

  1. Which of these diagnostic procedures involves radioactive decay of an unstable nuclide as the primary means for creating an image of the area of the body being studied?

    1. 1, 2 and 3

    2. 2 and 3

    3. 3, 4 and 5

    4. 1, 4 and 5

    5. 2, 4 and 5

  2. Four types of radiation arranged in order from lowest to highest health hazard is:

    1. gamma rays < alpha particles < beta particles < neutrons

    2. alpha particles < gamma rays < neutrons < beta particles

    3. beta particles < alpha particles < gamma rays < neutrons

    4. neutrons < alpha particles < gamma rays < beta particles

    5. gamma rays < beta particles < neutrons < alpha particles

  3. Write a chemical equation for each of the following radioactive decay processes:

    1. phosphorus-32 decays by beta-particle emission.

    2. lithium-8 decays by beta-particle emission followed by alpha-particle emission.

    3. potassium-40 decays by electron capture.

    4. nitrogen-13 decays by positron emission.

    5. thorium-232 decays by alpha-particle emission.

  4. Calculate the binding energy per nucleon in millions of electron volts for magnesium-27. The atomic mass of magnesium-27 is 26.9843 amu.

  5. Consider the following information:

    1. The layer of dead skin on our bodies is sufficient to protect us from most alpha-particle radiation.

    2. Plutonium is an alpha-particle producer.

    3. The chemistry of Pu4 + is similar to that of Fe3 +.

    4. Pu4 + + 4 e____> Pu, Eo = -1.28 V

Using this information, explain why plutonium is one of the most toxic substances known.