Each element has a chemical symbol: H is hydrogen, O is oxygen and C is carbon. A second letter is lowercase: Na is sodium.
A chemical formula shows the elements in a substance and their atom numbers or ratio. H₂O is water; CO₂ is carbon dioxide.
Read each capital letter as the start of a new element symbol. H₂O contains hydrogen and oxygen.
Hydrogen gas is H₂, oxygen gas is O₂ and chlorine gas is Cl₂.
These are diatomic molecules: two atoms of the same element joined together. They are still elements.
Reactants are the starting substances, on the left. Products are made, on the right.
The + separates substances. The → means “reacts to form”. Here, hydrogen and oxygen react to form water.
A word equation uses substance names. A symbol equation uses chemical formulae.
Read the formula or equation. Tap an answer and build your score.
Reactants on the left. Products on the right.
One point for each answer you get right first time.
No timer. Take your time and use a clue whenever you need one.