iMac 2011 21.5 inch

I have a iMac from mid 2011, and I want to put a newer version of macOS on it but it is 4 Gb and hdd if I put 16gb ram on it and an ssd can it work ? And can the ssd be external so it isn’t inside the iMac ?

submitted by /u/Inevitable_Initial63
[link] [comments]