what is the molar mass of a gas if 1.00g of the gas has a volume of 255mL at STP?

mass, m = 1.00 g
molar mass, M = ? g/mol
volume, V = 255 mL = 0.255 L
temperature, T = 298 K
pressure, P = 1 atm
gas constant, R = 0.082 atm L / (mol K)

PV = nRT
PV = (m/M)RT
M = mRT/(PV)

Molar mass, M = 1.00 × 0.082 × 298 / (1 × 0.255) = 95.8

1 mole occupies 24 dm^3 = 24,000 mL
Hence moles(gas) 255mL / 24,000 mL = 0.010625 moles.

Remember moles = mass/(g) / Mr.
mR = mass(g) / moles = 1 / 0.010625
Mr = 94.117
Mr (Krypton) = 84

So it could be Kypton. ?????