the gas is identified as follows
by use of ideal gas equation that is PV = nRT where n is number of moles calculate the number of moles involved
P= 507 torr
R(gass constant) = 62.364 L.torr/K.mol
T= 97 + 273 = 370 k
V = 500ml = 500/1000= 0.5 Liters
by making n the subject of the formula n = PV/RT
= (507 torr x0.5 L)/ 62.364 L.torr/Mol.k x 370 k) = 0.011 moles
the molar mass of the gas = mass/ number of moles
= 0.966/0.011= 88 g/mol = the gas is therefore Krypton since 88 g/mol is one of the isotope of krypton