Each group of numbers represents a country: Which is the odd one out .......... and why?
Perseverance is a great element of success. If you only knock long enough and loud enough at the gate, you are sure to wake up somebody. Henry Wadsworth Longfellow
Great solve 'colmaggio' (your 9th Challenge solve) nicely explained, indeed the element symbols spell out the country. Your 'Honorary Gold Medal' is on the way :o)
Ne P Al
P Er U
C H I Na
La Os
Bh U Ta N
Peru is the odd one out, as the others are in Asia
Sherlock Holmes: " Elementary my dear Watson, Elementary!"