The gas described in parts a and b has a mass of 1.66 g. the sample is most likely which monatomic gas?

Answer is: gas is argon (Ar).
Missing part of question find on internet:
part a: p(gas) = 1 atm, T(gas) = 20°C = 293,15 K.
part b: V(gas) = 1 L.
Ideal gas law: p·V = n·R·T or p·V = m/M·R·T.
R(universal gas constant) = 0,08206 L·atm/mol·K.
M = m·R·T÷p·V
M = 1,66 g·0,08206 L·atm/mol·K·293,15K÷(1 atm·1 L)
M = 39,9 g/mol (argon).

You know how the first one if filled up like the objects do the same but with the other categories