Observation

A cream precipitate is the observation. The conclusion is that bromide ions are present. Writing only “it went cream” is incomplete because it neither describes the precipitate precisely nor identifies the ion.

A plan may be designed to make observations, produce or characterise a substance, test a hypothesis, collect and check data, or explore a phenomenon. These purposes often overlap. For example, producing a salt may be followed by observations and measurements that help to characterise the product.