Concept preview

What you will be able to do

1. 01Distinguish qualitative from quantitative information
2. 02Define observation, interpretation, data and experiment
3. 03Explain the difference between a hypothesis, a theory and a law

Chemists describe substances in two complementary ways. Qualitative information is non-numerical: 'the liquid is blue', 'the metal is shiny', 'the reaction is fast'. Quantitative information is numerical: 'the mass is $110\ \text{kg}$', 'the temperature is $801\ ^{\circ}\text{C}$', 'the mark is $55/200$'. The two serve different purposes. Saying 'the boy is five feet tall' is a quantitative statement that makes no judgement, whereas 'the boy was extraordinarily tall' is qualitative and tells you an unusual situation exists. Good science uses both.