An ideal gas in a sealed container has an initial volume of 2.55 l. at constant pressure, it is cooled to 18.00 °c where its final volume is 1.75 l. what was the initial temperature?

Data Given:
                   V₁  =  2.55 L

                   T₁  =  ?

                   V₂  =  1.75 L

                   T₂  =  18 °C + 273.15  =  291.15 K

Solution:
             Let suppose the Gas is acting Ideally, Then According to Charle's Law,
                              P₁ / T₁  =  P₂ / T₂
Solving for T₁,
                              T₁  =  V₁ × T₂ / V₂
Putting Values,
                              T₁  =  (2.55 L × 291.15 K) ÷ 1.75 L

                              T₁  =  424.24 K
Or,
                              T₁  =  151 °C

Atomicity occurs to prevent updates of the database occurring only partially, which can cause greater problems than rejecting the whole series outright.some are monatomic, diatomic, triatomic etc because it shows the number of atoms. for example, monatomic means it contains only one atom.