We performed a study of the baryonic matter (stars and hot gas) budget  
inside X-ray detected groups at z<1 using the COSMOS survey, and  
compared it to that of local massive clusters. We constrain the  
stellar and total baryon mass fractions in groups: our results suggest 
that groups are not simple scaled down versions of clusters and that  
they are likely not closed systems, being more strongly affected by  
non-gravitational processes (such as AGN activity) than clusters. To  
have a better understanding of the importance of non gravitational  
processes in groups we study the energetics of radio galaxy feedback  
in X-ray detected galaxy groups and estimated the effect of the  
energy injection. We find that radio-AGN activity is capable of  
outweighing the capacity of a group to hold its gas. Furthermore,  
taking this energy injection into account we predict the deviation of  
the S-T relation from self similarity at the groups regime.