What is the correct RAM for a 2010 MacBook Pro?
According to the free app MacTracker, a mid-2010 Macbook Pro has:  Memory Slots 2 - 204-pin PC3-8500 (1066 MHz) DDR3 SO-DIMM. And has a maximum memory of 8 Gigs. I've read that Macs are sensitive to memory chips too. So I'd make sure the numbers above were followed. I upgraded my iMac with chips from Crucial. Works fine.