To identify a gas in an unlabeled gas cylinder, a sample was collected and found to have density of $\text {5.38 gm/L}$ at $\mathrm {15^°C}$ and $\text {736 mm(Hg)}$ pressure. Atomic mass of $\text {Sn = 118.7}$ amu, $\text {Te = 127.6}$ amu, $\text {Xe = 131.3}$ amu and $\text {Ba = 137.3}$ amu. What is the gas in that unlabeled gas cylinder?