Use 'i' in for loop to denote names of pre-defined objects

Question

I have 22 data frames called "chr_i" for i in (1:22). I want to print the dimensions of all of them. It would be a little time consuming to manually type dim() for each one, or to add them all to a list. There should be a way to write a quick for loop that cycles through them using i, but how do I let i denote the data frame?

for (i in (1:22)){
   b=paste0('chr_',i)
   dim(b)
}

just gives "chr_1" as a character and not the data frame.