B. A mixture of the properties of the elements that compose it.
Answer:
They attract or repel other charged objects without touching them.
Explanation:
My chemistry teacher always says like repels like opposite attracts.
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.
Hope this helps
-use headphones
-do not take up extra seats/space using their luggage or bags
-be aware of their surrounding so they do not bump into people or step on their feet
