It's simple what they're asking for is for you to that each element in the periodic table there is a certain number in their labeling the elements starting them off from 1 to 32 or so. So what it wants you to do is that you start from the top of the table counting down since it says period 5 so period 5 starts at 37 RB so start naming the number of those elements in those following columns just like 37 RB
after that say 38 SR, 39 Y, 40 ZR and so on and so forth
Hope this helps!!
Please mark me as brainiest if I helped you out!!
