Ryzen 3000-series will run on B450+ and X470+, based on current specs. Obviously, at some point there will be a future motherboard release that will change the +'s to ranges.
But B5xx I also meant X570. Anyway, I am almost 100% sure, it won't work on A320, as the someone in the message abovedesired to run it on. And it is unclear if there will be updates for the BIOS for cheaper B450s.
Some A320 boards actually do support Ryzen 3000 with a BIOS update, like the one below. I wouldn't really recommend getting them because you'll probably need to flash the BIOS, but they can be used.
Please change the attitude. A320 does not officially support the 3100 and 3300x the poster above mentioned. Please pay attention when replying, otherwise you come across as rude.