Points to consider
The concept of rate is very useful in chemistry as it often gives us clues to the relative reactivity of various elements or compounds.
Many of the judgements made about reactivity are based on observations about rate.
Consider the following question, which relates to an experiment where various materials are placed into acid.
Which one of the materials added to the acid is the most reactive – A, B, C or D?
How have you decided which is the most reactive?
What information could you use to give a number to the level of reactivity?