Which separation technique is used to separate helium from a mixture of helium and methane

Select all of the methods through which a drug can enter your body. injection swallowing inhalation absorption

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false

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?