• $X$ is 5.
  • $U$ is 9.
  • $O$ is 0 or 7.
  • $I$ is 4 or 5 or 7.

What is $V$? And what is $K$ (two options)?

  • $\begingroup$ Inspired by this puzzle, but the underlying pattern is not the same. $\endgroup$ – Rand al'Thor Jun 9 '19 at 20:42

I think that

$V$ is $2$
$K$ is $1$ or $3$


Find the elements in the periodic table whose chemical symbol begins with the letter. The associated numbers are those in the tens position of the corresponding atomic numbers.


$X \rightarrow$ is Xenon (Xe) whose atomic number is 54
$U \rightarrow$ Uranium (U) with atomic number 92
$O \rightarrow$ Oxygen (O) and Osmium (Os) with atomic numbers 08 and 76
$I \rightarrow$ Indium (In), Iodine (I) and Iridium (Ir) with atomic numbers 49, 53, 77
$V \rightarrow$ Vanadium (V) with atomic number 23
$K \rightarrow$ Potassium (K) and Krypton (Kr) with atomic numbers 19 and 36.

Note: Oganesson (Og) has not been included here, either it is too new or we are only considering elements less than 100.

| improve this answer | |
  • 1
    $\begingroup$ Brilliant! You got it. (I was expecting this one to be solved quicker - just came now to add a hint.) $\endgroup$ – Rand al'Thor Jun 13 '19 at 8:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.