Hey there, @Reso__!
I'd strongly recommend you backup what you can access from the data on the 500 GB HDD somewhere else as soon as possible! Your 1 TB HDD won't get affected from the bad sectors on the other hard drive, however, your whole system could suffer performance issues if the HDD completely fails.
The bad sectors cannot be fixed and the more you use this damaged drive, the worse its condition is going to get. All the contents on this drive are currently in jeopardy due to these bad sectors. I'd advise you to backup your files and consider replacing the drive immediately!
"A bad sector is a sector on a computer's disk drive or flash memory that is either inaccessible or unwriteable due to permanent...