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Frictional forces acting on an object are often converted into energy, which causes the temperature of the object to rise slightly.

Which of these conditions most likely produces an unstable isotope?

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?