This paper aims to resolve the problem of formation of young objects observed in the RCW 82 H II region .
In the framework of a classical trigger model the estimated time of fragmentation is larger than the estimated age of the H II region .
Thus the young objects could not have formed during the dynamical evolution of the H II region .
We propose a new model that helps resolve this problem .
This model suggests that the H II region RCW 82 is embedded in a cloud of limited size that is denser than the surrounding interstellar medium .
According to this model , when the ionization–shock front leaves the cloud it causes the formation of an accelerating dense gas shell .
In the accelerated shell , the effects of the Rayleigh–Taylor ( R-T ) instability dominate and the characteristic time of the growth of perturbations with the observed magnitude of about 3 pc is 0.14 Myr , which is less than the estimated age of the H II region .
The total time t _ { \sum } , which is the sum of the expansion time of the H II region to the edge of the cloud , the time of the R-T instability growth , and the free fall time , is estimated as 0.44 < t _ { \sum } < 0.78 Myr .
We conclude that the young objects in the H II region RCW 82 could be formed as a result of the R-T instability with subsequent fragmentation into large-scale condensations .

Key words : H II regions – hydrodynamics – instabilities – ISM : individual objects ( RCW 82 ) – stars : formation