Element Guessing Game (Periodic Table Puzzle)

How to use the Element Guessing Game (Periodic Table Puzzle)

1. Type an element’s name or symbol and press Guess.
2. Each guess is compared with the mystery element across eight columns. Green means the same value. For atomic number and mass, an arrow shows whether the mystery element is higher or lower.
3. Use the clues about group, period, category, block and state to narrow it down. You have ten guesses.
4. Choose Unlimited for a new random element, or Daily element for the one everyone gets that day.

Example

Worked example (a fictional game where the mystery element is Calcium)

• Guess Iron (Fe): Atomic number 26 is higher than 20, so ⬇; group 8, category transition metal and block d do not match; period 4 and state Solid match
• Guess Magnesium (Mg): Group 2 matches, category alkaline earth metal matches, block s matches, and state Solid matches, but period 3 is not period 4 and atomic number 12 is lower than 20, so ⬆
• Guess Calcium (Ca): Every cell is green and you win

Limitations

• For elements with no stable isotope, the mass shown is the mass number of the longest-lived isotope, which is the usual convention.
• The categories follow a common classification, and sources differ for a few elements such as astatine, polonium and the heaviest synthetic elements.
• The f-block elements (lanthanides and actinides) are shown with no group number.
• State is the state at normal room temperature. Some synthetic elements have not been made in large enough amounts to know, so they show as unknown.
• Atomic masses are rounded to three decimal places and are the standard values for elements that have one.
• This is an independent game and is not affiliated with any publisher or other game of a similar style.

Sources

• chemical-elements dataset (cheminfo mass-tools, MIT)

Rates and rules last checked against these sources on 2026-10-08.

About this tool

The Element Guessing Game hides one of the 118 chemical elements. Guess an element by name or symbol, and the game compares it with the mystery element on atomic number, atomic mass, group, period, category, block and state at room temperature. Green means a match, and arrows show whether the mystery element has a higher or lower number. You have ten guesses. It is a quick, free way to learn the structure of the periodic table.

Also searched for as: periodic table guessing game, guess the element, chemistry wordle, element puzzle, periodic table quiz game, guess the chemical element.

Element Guessing Game (Periodic Table Puzzle) is part of ToolStack Hub's Browser Games. It runs entirely in your browser, which keeps your data private and makes results instant. There is nothing to install and no account to create. There is no usage limit.

Frequently asked questions