• Substances consist of microscopically small parts, such as atoms, molecules and ions.
• Microscopic level phenomena (interactions and reactions) cannot be observed directly.
• In contrast, macroscopic level phenomena can be observed with human senses, such as hearing or sight.
• When a match is scratched at a microscopic level, the phosphorus on the surface of the box reacts strongly with potassium chlorate at the end of the match.
• However, at the macroscopic level, this is observed as a rapidly lit and burning yellow flame, alongside smoke and heat.