burning sulphur divides it into smaller sulphur particles

An example of the alternative conception that substances retain their identity after chemical reaction.

"'Tis well known that when we burn Sulphur, the Sulphur does not perish, but only is divided into such small particles, as are remov'd from our view: and accordingly in this experiment I saw an infinite [sic] number of very small sulphureous particles, sticking to the inside of the Glass, which appeared to me to be round."

Anthony Van Leewenhoek

The famous microscopist van Leewenhoek writing to the Royal Society in 1700. Quoted in: Tinniswood, A. (2019). The Royal Society & the Invention of Modern Science. Basic Books.

The notion of chemical change as involving the 'disappearance' of one (or several) substances and the 'appearance' of one (or more) other substances is a critical idea in chemistry – an idea complicated by the continuity of the elements when understood not as substances but more as principles within substances.

Chemical change (such as combustion) is thus inherently different to physical change (such as melting) where the same substance changes its state. Understandably, learners often struggle to make good sense of these abstract ideas.

This reflects the historical development where scientists only slowly developed the modern concepts. van Leewenhoek might well have seen small particles of sulphur that had evaporated due to the heat of the combustion and re-condensed, and so avoided reaction.

Read about the nature of alternative conceptions

Read about some examples of science misconceptions

Read about historical scientific conceptions

Author: Keith

Former school and college science teacher, teacher educator, research supervisor, and research methods lecturer. Emeritus Professor of Science Education at the University of Cambridge.