Write the word or phrase beginning with each letter of the word change

What is the molecular formula of a hydrocarbon with m+ = 166? (write the formula with no subscripts, e.g. c4h10.) what is the sum of rings and double bonds in this compound?

In which phase(s) do the molecules take the shape of the container?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.