Combine

Combine two species to form new compounds, with one strict rule: a reaction only works if every atom is conserved. Build a tree of discoveries from your starting set and reach the target compound.

• Fuse two species to attempt a new compound
• Only mass-conserving, balanced reactions are accepted
• Add each successful product to your bank of discoveries
• Reach the target species, faster solves and more finds score higher

• Easy, Medium or Hard difficulty
• Daily goal or Practice for fresh targets

• Desktop: drag and click to pick the two species you want to fuse
• Phone & tablet: tap or drag to select and combine species

• Count atoms on both sides before committing, unbalanced pairs just fail
• Build versatile intermediates that open several later reactions
• Watch the timer and chase the chain that leads most directly to the target

Combine is a chemistry crafting puzzle about reactions and compounds, with conservation of mass as the rule you cannot break.

• Skills: chemical reactions, compounds, conservation of mass, chemical formulas
• Best for: roughly grades 8–12 (ages 13+)
• For parents & teachers: reaction chemistry through hands-on combining.

Combining species into compounds only when every atom is accounted for is conservation of mass — Lavoisier's principle that matter is neither created nor destroyed in a reaction.

Building a tree of discoveries from a starting set is the original structure.

Making conservation the gate rather than a rule to recite is the right way round. It is the constraint that makes chemistry countable: what you can reach is fixed by what you started with, so the tree has a shape rather than being open-ended.

Combine is a chemistry crafting puzzle about reactions, compounds and conservation of mass. It's an original, free browser game made in-house for PlayPendium.

A free, original browser game on PlayPendium. No download, no install.