Answer:
But-2-ene is your answer i guess
Mass is density times volume
0.760 x 531 = 403.56g
404g if 3 sig figs
The velocity of the gas is inversely proportional to the square root of the molar mass of the gass. Heavier molecules tend to travel slow compared to light molecules. Among these, He has the lowest molar mass of 4 g/mol hence this element has the greatest velocity among all molecules given.
<span>A full valence electron shell.</span>
I think the answer is A. Hope that helped :)