6
$\begingroup$

As I wrapped up another long day of running experiments with only mediocre yields, I prepared to turn off the fume hood and go home. However, before I left, a note caught my eye—my professor had signed it with his name and left it in my locker! Attached is what he wrote on the note. Can you figure out the missing number, and what my professor was trying to tell me?

\begin{array}{c|c|c|c} & \mathbf{1 5} & \mathbf{1 6} & \mathbf{1 7} \\ \hline \mathbf{2} & -1.4 & ? & 3.2 \\ \hline \mathbf{3} & 2.1 & -2.8 & -5.9 \end{array}

Here's a markdown version:

15 16 17
2 -1.4 ? 3.2
3 2.1 -2.8 -5.9

Hint:

The numbers in the table are physical constants.

Hint 2:

The constants in the table are very particular base-ten logarithms, which are relevant to the theme of the puzzle.

Improve this question
$\endgroup$
6
  • $\begingroup$ Are these numbers approximate or exact? $\endgroup$
    – Benjamin Wang
    Commented May 20 at 8:51
  • $\begingroup$ Well, no physical numbers are exact. Take that how you will. $\endgroup$
    – Auride
    Commented May 20 at 12:14
  • $\begingroup$ rot13(Ner gur ahzoref fbzrubj eryngrq gb cbjref bs gra va fpvargvsvp abgngvba??) $\endgroup$
    – Dreopa
    Commented May 22 at 12:25
  • $\begingroup$ @Dreopa rot13(Gurl ner eryngrq gb cbjref bs gra va n irel cnegvphyne jnl.) $\endgroup$
    – Auride
    Commented May 22 at 16:13
  • $\begingroup$ I'm not a chemist so before I spend more time looking at wiki pages rot13(ner gur ahzoref eryngrq ng nyy jvgu gur ryrzragf va gur cbfvgvbaf tvira ol gur neenl vaqrkvat va gur crevbqvp gnoyr?) $\endgroup$
    – Fluorine
    Commented May 24 at 9:16

1 Answer 1

Reset to default
2
$\begingroup$

The chemistry theme and logarithm based 10 makes me think of pH, and the numbers 15, 16, 17 are elements P, S and Cl. 2 and 3 don't really make sense as elements, but might refer to rows in the periodic table, so the row above might refer to the elements N O and S. After some digging I found pKa (acidity) of HF is 3.17, of HCl is -5.9, H2SO4 is -2.8, H3PO4 is 2.14 (first pKa), HNO3 is -1.4, these seem to be the most common or stable forms of acids of the respective elements (AFAIK, I'm no chemistry expert).

The missing element is Oxygen, and pKa of H2O is 14. But I'm not sure what the professor is trying to convey with it. Maybe he's telling the narrator to drink more water? Or don't ignore the obvious or exceptions to the rule? Or something's wrong with the solvent?

Improve this answer
$\endgroup$
1
  • $\begingroup$ Correct! The solution I was looking for was "drink more water," presumably because the narrator has been spending too much time in the lab. $\endgroup$
    – Auride
    Commented Jun 20 at 19:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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