Ram question

Basically my mob has 2 ram slots and i accidently bought 4000 mhz 8 gig ram stick.

The point is can 2 different mhz 8 gig ram stick work with each othor?

Yes they will throttle down to match the lowest frequency stick.

It might work, but it's not a good idea. If your motherboard is running the RAM in dual channel mode and they are mismatched, it can lead to a BSOD nightmare. Always best to use a matching RAM set.