What action leads to crystal formation in minerals?
a.
the atoms and molecules join together.
b.
chemicals break apart.
c.
temperature changes create unusual shapes.
d.
the atoms or molecules form repeating structures.

Before it was launched, a helium-filled balloon had a pressure of 201 kpa at a temperature of 27°c. at an altitude of 15,000 m, the pressure had decreased to 2.5 kpa and the temperature had dropped to -14 °c. the volume of the balloon increased to 59.3 m3. what is the original volume of the balloon? 13 m3 0.85 m3 0.077 m3 1.17 m3