Need help finding compatible motherboard

[The_Yotes]

Hello, I'm trying to help my cousin upgrade his old pc which was originally mine but I gave it to him after I upgraded my pc. He wants to upgrade it so I am looking for some new ram and motherboard but I cannot find a motherboard that will 100% go with the ram that he has right now. Can anyone help me? The ram he has now is https://www.newegg.com/corsair-16gb-288-pin-ddr4-sdram/p/N82E16820236417 this. I'm not too sure if the CPU will go with it but I read somewhere that if the ram goes with the motherboard, it goes with the CPU and I'm not totally sure about that so I've come here for help. If the rest of the PC specs are needed I can let you know. If there is an easier way to go with this I wouldn't be apposed to it and I'm sure my cousin wouldn't be either.

[The_Yotes]

1 minute ago, 8tg said:

It’s DDR4, it’ll work in any motherboard that supports DDR4

ie any current gen platform and all the way back to Intel Skylake and first gen AMD Ryzen such as Intel H110, Z170 or amd A320 or X370

And anything newer.

 

will it still work if it says DDR4 3200 when the memory standard for a motherboard I'm looking at says 2666, 2400 and 2133? Also would we need a new cpu or could we use the old one from the old pc

[The_Yotes]

1 minute ago, 8tg said:

The memory will clock down to match the rated speed of the board. If it’s an older board that only supports 2133 or 2400mhz, it’ll only run at those speeds.

If it’s a board that supports memory overclocking in any form it will be able to run at 3600mhz as it’s rated.

The speed of ram is mostly standardized, the speeds on higher speed ram are what it’s tested and rated to overclock to.

 

As for the cpu and motherboard, that depends on what they have now. You can’t put some old cpus on more recent motherboards, and vice versa.

So will this 
https://www.newegg.com/core-i7-9th-gen-intel-core-i7-9700k/p/19-117-958
https://www.newegg.com/p/N82E16813145237?Description=z390%20motherboard&cm_re=z390_motherboard-_-13-145-237-_-Product&quicklink=true 
https://www.newegg.com/corsair-16gb-288-pin-ddr4-sdram/p/N82E16820236417
all go together? 

[The_Yotes]

Would we need a new cooling system with everything else or a new gpu? Right now the old pc has a Geforce GTX 1050.