How do you feel about your performance on this "STEP TEST"?

Which statement justifies that phosphine (ph3) is a polar molecule?

Which of the following describes a compound? (hint: carbon and oxygen bo a. a piece of pure carbon, containing only carbon atoms b. oxygen gas surrounding a solid piece of carbon c. a substance made of two oxygen atoms for each carbon atom carbon and oxygen atoms mixed without being bonded together

How many moles are contained in 5.6 l of h2 at stp