Wednesday, September 29, 2004

Children's Science Books

When you pick a book from the library to teach your kids about science, you expect a little accuracy, right?

This is part of a letter I wrote the library:

In your collection you have the book The Elements Carbon by Giles Sparrow, Benchmark Books.

We checked this out to teach our daughter about carbon, and I was startled to find a large number of errors and omissions in this 30-page book. I list these below. Some are merely careless, but others are egregious enough to merit reconsideration of the author and/or the series. I will not critique the writing style at this time; I'm a physicist, not a professional writer.


Page 4, Paragraph 3. Atoms cannot be seen even with 'extremely powerful microscopes.' There is a way of imaging some atoms in arrays, but this is not a microscope as understood by the children who read this.

Paragraph 4. 'which move around the nucleus in shells' is wrong. No simple description will be accurate, but you could use 'orbit nearer or farther from the nucleus in patterns we call energy shells' and be far more accurate.

Paragraph 5. 'Atoms are only stable if their outer electron shell is full.' This is misleading at best. (Ask yourself 'What does "stable" mean?') Instead say something more like 'Atoms don't combine easily with other atoms if their outer electron shell is full. Very heavy atoms are a little more complicated.'

Page 5, Paragraph 2. 'Carbon is very reactive.' This is wrong. Say instead 'Carbon reacts with many other atoms.' The term 'very reactive' means that it takes little or no added energy to initiate the reaction.

Page 6. The image of pencils is captioned with a claim that pencil lead is really graphite. However, all the pencils in the picture are colored pencils--which use plastics and clay, but not graphite!

Page 7, Paragraph 3. 'Diamonds can only be split by an expert who knows . . .' This is false. A non-expert can break one too, for instance by dropping it on the floor. Say instead something like 'Diamonds can be split by a blow along a direction in what is called the plane of cleavage. Experts use these to help shape diamonds for jewelry.'

I omit various complaints about a global warming screed, fuzziness in distinguishing compounds and mixtures, misunderstandings about plastic decompostion, etc.

Page 27. The pictures ought to clearly distinguish the double bond from the single bonds. This is standard practice; I don't know why the author didn't do it here.

Page 28, Paragraph 2. Instead of 'The character of an atom depends on how many even tinier particles called protons there are in its center, the nucleus,' say the correct 'The character of an atom depends on how many of the tinier particles called electrons it has. An atom has the same number of electrons and protons. The protons are in its center, the nucleus.' Atomic properties are determined by the electrons in the atom.

The book also omitted simple things like an explanation of why the columns for non-metals don't go all the way down in the periodic table, where C14 comes from, and other things referenced and left mysterious in the text.

The pictures of graphite pencils have no graphite in them, and pictures of double bonds look just like single bonds, I think somebody's editor was out to lunch. I wouldn't trust anything in this series.

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