The Density of Neon is Highest at (1) STP (2) 0°C, 2 atm (3) 273K, 1 atm (4) 273°C, 2 atm

Answer: (2)

In neon lamps, we see that neon is colored reddish-orange. It is the second lightest among noble gases. Neon finds application as it is an affordable refrigerant alternative compared to helium. If we consider unit volume then the cooling power of neon is 40 times more than liquid helium. 

As per gas equation, PV = nRT

Or, PV = RT. (w/m)

If we rearrange the equation, we get, P.M = RT. (w/V)

Replacing (w/V) by d we can write: PM = dRT

We can conclude that density and temperature are inversely proportional while there is a directly proportional relationship between pressure and density.

Therefore, density will be highest at the lowest given temperature (0 degrees Celsius) and high pressure (2 atm).