What type of ion is represented in the structure in the figure below, and what is its charge? A.Cation ,-1
B.Cation,+1
C.Anion,-2
D.Anion,-1

Until well in the 60ties, the luminous dials of wrist watches and alarm clocks were marked with luminous paints containing Radium (Ra-226) or Promethium (Pm-147). These kind of watches are no longer manufactured today. This is not due to the radiation exposure to the persons wearing the watches but because of the radiological risk for the persons manufacturing them.

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