Radiation Safety Practice Exam

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Study for the Radiation Safety Exam. Test your knowledge with multiple choice questions, each equipped with hints and explanations. Prepare effectively and confidently!

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What is the atomic number of promethium?

  1. 60

  2. 61

  3. 62

  4. 63

The correct answer is: 61

Promethium is a chemical element with the symbol Pm. Its atomic number is defined as the number of protons in the nucleus of an atom of an element, which also determines the identity of the element itself. For promethium, the atomic number is 61. This means that promethium has 61 protons in its nucleus, which categorizes it as a member of the lanthanide series of the periodic table. Knowing the atomic number is crucial in understanding the behavior of the element in chemical reactions and its placement on the periodic table. Promethium is unique not only because it is the only radioactive rare earth element, but also because all of its isotopes are unstable. The atomic number is foundational information that informs scientists and students about the properties and applications of promethium.

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