What is the mass (in grams) of 10.00 L of propane vapor (C3H8) at STP?

There is one girl i like and i don't know how to tell her that, i have a feeling she knows but if she doesn't i don't want to make a fool out of myself how is one way to boost my confidence on asking her out

Which of these is a physical property

Anyone who's in connections academy chemistry b have the factors that affect the rate of a reaction portfolio already done?