Answer:
Noble gas is Ne
Step-by-step explanation:
Let's make the expression for the Ideal Gases Law at STP
Temperature = 273K
Pressure = 1 atm
1 atm . 1.409L = n . 0.0821 L∙atm/mol∙K . 273K
1.409 L.atm / (0.0821 L∙atm/mol∙K . 273K) = n
0.0628 mol = n
Let's calculate the molar mass to find out the noble gas
1.269 g / 0.0628 m = 20.2 g/m
BE CAREFUL BECAUSE THIS ARE WRONG IN THE STATEMENT.
12.69 g
14.09 L