One half of Barium-139 decays into another element after 86 minutes. The 86 minutes is referred to as this element's... Select one:
a. half-life.
b. radioactive phase.
c. time zone.
d. quarter time

Aroom with dimensions 7.00m×8.00m×2.50m is to be filled with pure oxygen at 22.0∘c and 1.00 atm. the molar mass of oxygen is 32.0 g/mol. how many moles noxygen of oxygen are required to fill the room? what is the mass moxygen of this oxygen?