1Rx8 = Single-Rank

The RAM is generally compatible with the motherboard and CPU. However, if you buy the B350 motherboard new, a BIOS update with a 1st generation Ryzen processor may have to be performed first so that you can use the 2nd generation Ryzen processor. Are you buying the motherboard new or used? Are you upgrading from Ryzen 1 to Ryzen 2? Otherwise, I recommend a 400 series motherboard (e.g. B450), which are compatible with 2nd generation Ryzen processors out-of-the-box.

Well, the specifications of the motherboard do not list ddr4-3200 RAM. So I wouldn't risk it. Even if it would run, it doesn't make sense to buy RAM that runs slower than possible. And also I wouldn't buy a b350 board anymore but the newer b450 chipset, just as a suggestion.

sieh dir diesen link an da siehst welche am zu deinem mainboard passen: https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/TUF_Z270_MARK1/Z270_PRIME_TUF_STRIX_QVL.pdf oder direkt von kinston: https://www.kingston.com/de/memory/search?model=95744&devicetype=7&mfr=ASU&line=270%20Motherboard