One typical reaction to explore, at secondary level, is the rate of reaction between magnesium and hydrochloric acid. The instructions on a worksheet may state 'time how long it takes for the magnesium to disappear'. This is unhelpful if we're trying to teach the concept that a chemical reaction is taking place. The language we use to describe chemical change is vitally important.

Asked to state what is happening at the surface of the magnesium, many will struggle as the concept of particle collisions may not be well understood.

[INSERT RATE_EU_01_ani]