Chemical literacy revisited

Peter Atkins offers his diet for a minimum core for an education in chemistry.¹ A rich diet, but is it healthily balanced?

Much of an education in chemistry will depend on who it is for. Atkins' proposals are for ' . someone with a passing need to understand a bit of chemistry - engineers, biologists, physicians, physicists . the cultivated "man in the street" .'. It is here that a problem arises. Those of us involved in writing the Twenty first century science curriculum² began with the premise that it is not possible to address the needs of both the specialists (the future engineers and physicians) and the generalists (the wider general public) within a single curriculum. We thus developed a core curriculum for scientific literacy and an optional, additional curriculum for those who may want to take their study of science further. This curriculum, for students aged 14-16 in the final stage of compulsory schooling in England, is now being piloted in ca 80 schools across the country.

In developing the core curriculum for scientific literacy, we thought about chemical literacy, and asked ourselves the question: 'What are the elements of chemistry that every member of the public should know, long after they have forgotten the details of the science they learned in school?'. We drew on earlier work³ and did a consultation exercise,⁴ the results of which helped inform the chemical content of the Twenty first century science core. Building on this work, and as a contribution to debate, I offer the following as my suggestion for the core of chemical understanding, which I think every member of the public should know - assuming their formal study of science ends at the age of 16.

The key principles 

1. Everything is made of atoms and molecules, which are very small and move all the time.
2. Elements appear in different disguises - different species of the same element (atoms, molecules, ions) behave very differently.
3. Chemical compounds have a fixed, unvarying composition - every pure substance has a fixed formula, however it is made.
4. The idea of chemical change - when a chemical change occurs, atoms join together in a different way.
5. Properties of substances depend on their molecular structure - the shape of a substance's molecules, and the way they fit together, decides what the substance is like.
6. 6. The power and limitations of science - how scientists try to answer questions; the questions which science can and cannot answer.  

My list is based on the proposition that it is better to have a sound understanding of a smaller number of really important principles than to have a partial understanding of a larger number. Everyone would be better off with a complete if simple understanding of what happens in a chemical change than with a collection of disconnected bits and pieces collected from their years studying science in school.

Comparing this list with Atkins' core, there are some noticeable differences. First, mine stops well short of Atkins' core in terms of sophistication of chemical understanding - for example, there is no mention of periodicity or of the electronic theory of bonding in my list. But remember, my list is for the scientifically-literate man or woman in the street whose science education may end at age 16. Future engineers and scientists will need to have a more advanced and sophisticated understanding than this minimum. Clearly Atkins' man in the street is cultivated - but I wonder, apart from its wonderful intellectual satisfaction, what value an understanding of, say, the electronic theory of bonding has for the public as they seek to make sense of the issues that confront them daily in the papers.

Second, I am surprised that Atkins makes no reference to the critical idea of constant composition. Any chemist who has tried to have a scientifically informed debate about the merits of organic food will know the frustration of trying to explain that nutrients are chemically identical whatever their provenance. Ever since 1828 when Wöhler disproved the 'vital force' theory, chemists have realised that there is no fundamental difference between the same compound made by natural means or otherwise. Vitamin A from an organic carrot is the same as vitamin A from a non-organic one, and the debate would move forward if everyone understood this.

Thirdly, Atkins makes no reference to my sixth item, the power and limitations of science itself. Yet, for the man or woman in the street, this is arguably more important than any of the chemical concepts in the list. So many of the debates around scientific issues - air quality, organic food, climate change - depend on an understanding of the way scientists collect and use data and the uncertainty that is associated with it. Science has been the dominant culture of the last century and may well continue to be in this one, and people expect science to offer certain proof. Much of what students learn in school - my first five chemical principles - is now uncontested, yet it is through uncertainty and disagreement that science moves forward, and the scientifically-literate man or woman in the street needs to appreciate this. An understanding of the scientific process - the ways scientists collect and use data, look for correlations and causes, produce and test theories and eventually make recommendations for action - is as important for understanding the issues around climate change as understanding the rearrangement of atoms during combustion.

In the end, any proposals for a core curriculum in chemistry, or any other subject for that matter, come down to individual and collective judgement. There are no Mosaic tablets on which such things are written, not even those passed down from the Qualifications and Curriculum Authority (QCA). So, in that spirit, let's have a debate. What, for you, constitutes the irreducible core of understanding for a chemically-literate citizen?

Professor John Holman is director of the National Science Learning Centre at the University of York, Heslington, York YO10 5DD.

References

1. P. Atkins, Educ. Chem., 2005, 42(1), 20.
2. 21st century science project team, Sch. Sci. Rev., 2003, 85(310), 27.
3. J. Holman, Educ. Chem., 2001, 38(1), 10.
4. J. Holman and A. Hunt, Educ. Chem., 2002, 39(1), 12.