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Puzzle CreationIntermediate8 min read

How to Create a Puzzle Using Chemical Elements

The periodic table offers rich puzzle possibilities. Use atomic numbers, element symbols, and chemical formulas to create science-themed geocaching puzzles.

Why Chemical Elements?

Chemistry-based puzzles appeal to a wide audience and offer multiple encoding methods:

  • Atomic numbers — Perfect for generating coordinate digits
  • Element symbols — Spell words using periodic table symbols
  • Atomic masses — Use molecular weights for calculations
  • Educational value — Great for science-themed or school-area caches

Key Elements for Puzzles

These elements are particularly useful for coordinate digits (1-9):

H

1

He

2

Li

3

Be

4

B

5

C

6

N

7

O

8

F

9

Ne

10

Tip: For two-digit numbers, use Neon (10) through Calcium (20) or combine single digits (Carbon + Nitrogen = 67).

Method 1: Atomic Number Encoding

The most straightforward approach—atomic numbers become coordinate digits:

Example puzzle:

"The coordinates are hidden in these elements:"

N: Boron, Hydrogen, Carbon, Nitrogen, Boron

→ B(5), H(1), C(6), N(7), B(5) → N 51° 67.5

Make it thematic by presenting elements in a chemical context:

"Analyse this compound to find the latitude: BHC₃N₂B (atomic numbers give the digits)"

Method 2: Element Symbol Spelling

Many words can be spelled using element symbols. Our Element Decoder can help find these combinations:

CaCHe = Ca + C + He (Calcium, Carbon, Helium)

GeNiUS = Ge + Ni + U + S (Germanium, Nickel, Uranium, Sulfur)

TiN = Ti + N (Titanium, Nitrogen)

Spell a keyword, then use atomic numbers of those elements for coordinates.

Method 3: Chemical Formula Calculations

Use real chemical formulas and their properties:

"The minutes of latitude equal the total atomic number of water (H₂O)"

  • H₂O = 2×H + 1×O = 2×1 + 1×8 = 10

"Use the molecular mass of carbon dioxide (CO₂) rounded to nearest integer"

  • CO₂ = 12.01 + 2×16.00 = 44.01 ≈ 44

Use our Chemical Formula Parser to verify calculations.

Complete Example Puzzle

Cache Title: "Elementary, My Dear Watson"

Cache description:

"Sherlock would approve of this chemical puzzle. Analyse these compounds to reveal the final location. All you need is elementary knowledge."

Your coordinates: N A°B C.D E F    W G°H I.J K L

A = Atomic number of Boron

B = Number of protons in Hydrogen

C = Atomic number of the element with symbol "C"

D = Total atomic number of OH (hydroxide)

E = Atomic number of Beryllium

F = Number of electrons in Lithium

G = First digit of Neon's atomic number

H = Second digit of Neon's atomic number

I = Atomic number of Helium

J = Atomic number of Carbon minus Hydrogen

K = Atomic number of the lightest noble gas

L = Atomic number of Nitrogen

Solution:

A=5, B=1, C=6, D=9 (O=8+H=1), E=4, F=3, G=1, H=0, I=2, J=5, K=2, L=7
N 51° 69.43, W 10° 25.27

Difficulty Variations

Easy (D1.5-D2)

  • Use common elements (H, C, N, O)
  • Provide element names, not just symbols
  • Simple "atomic number = digit" encoding

Medium (D2.5-D3)

  • Use only element symbols
  • Include less common elements (Sc, Ti, V)
  • Require simple calculations with formulas

Hard (D3.5+)

  • Use molecular mass calculations
  • Reference electron configurations or isotopes
  • Combine with other cipher types

Pro Tips

  • Double-check your chemistry. Verify atomic numbers and masses using a reliable source. Mistakes frustrate solvers.
  • Keep it accessible. Most geocachers aren't chemists. Stick to well-known elements for easier puzzles.
  • Use visual aids. Include periodic table images with relevant elements highlighted.
  • Create a theme. Chemistry fits well with lab themes, school locations, or famous scientist tributes.