I dont know how to do this

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure

How many neutrons does an element have if its atomic number is 50 and its mass number is 166

What two factors can affect the properties of a hydrocarbon? a. the number of its carbon atoms and the number of single bonds b. the number of its carbon atoms and the arrangement of its atoms c. the arrangement of its atoms and the number of its double bonds