8.0 g of a monoatomic gas occupies 96.0 L at 380.9 mm Hg and 20.0 °C. What is the identity of the gas?

The monoatomic gas : He

In general, the gas equation can be written  

where  

P = pressure, atm  

V = volume, liter  

n = number of moles  

R = gas constant = 0.08206 L.atm / mol K  

T = temperature, Kelvin  

P 380.9 mmHg = 0.5 atm

T 20 C+273 = 293 K

We can find molar mass of gas :

monatomic gas means a single element, usually a noble gas. The noble gas element with mass 4 is He

c. electrical charges of ionic bonds.