How the game works
A grid of cards fills the screen. Each card shows a symbol, a name and an atomic number, and is colored by family: alkali metals, alkaline earth metals, transition metals, nonmetals, halogens, noble gases and metalloids. Post-transition metals such as aluminium, tin and lead have their own silver-grey color, and uranium, an actinide, has a brown one. A question appears at the top in one of three forms: find an element by name, say which element a symbol belongs to, or find the element with a given atomic number.
The grid starts with 14 cards and adds two per level, up to 28, and a level is eight questions. Level 1 gives you 14.5 seconds per question, and each level takes half a second off, down to 10 seconds from level 10. A correct answer scores 100 points, a bonus for the time left, and 20 more for every answer already in your streak. A wrong answer or a timeout costs one of three lives and resets the streak, and the right card is highlighted. A correct answer is followed by a short fact card.
The deck also includes a few compounds and alloys, such as limestone and electrum. They are not elements, but they come with their own facts.
What it is good for, and what it is not
Chemistry Freex is good at recall: symbols, names, atomic numbers and which family an element belongs to. It does not teach electron configurations, bonding or reactions, and it covers 44 of the 118 elements. Treat it as practice for the parts of a chemistry course that come down to memorization.
Tips for students
- Learn the odd symbols first. Na is sodium, K is potassium, Fe is iron, Au is gold and Ag is silver. Their symbols come from Latin names, which is why they do not match the English ones.
- Use a few anchors for atomic numbers. Carbon is 6, oxygen 8, iron 26 and gold 79. Most other numbers are easier to place relative to those.
- Read the explanation after a mistake. It is the most useful moment in the game, and also the easiest one to tap past.
- Pay attention to the colors. After a few sessions, the family colors start to tell you roughly where an element sits in the table.
For teachers
The game needs no login and no install, and it runs on laptops, tablets and phones. Share the link gamefreex.com/game/elementeex and students can open it straight away.
Next step: Molecule Freex
Molecule Freex moves from single elements to compounds. Each round shows a molecule's structure with empty slots, and you drag in the right atoms before a 30 second timer runs out: water (H₂O), carbon dioxide, ammonia (NH₃) and methane (CH₄) early on, sulfuric acid, ethanol and glycine later. The structures show the basic shapes, like bent water and straight carbon dioxide, and each finished molecule ends with a short fact.