Before you read this, I suggest you read posts 16.39, 17.44 and 19.5. The word “cell” in this post means an electrical cell and not a biological cell, as described in post 16.18; so the word “cell” is another possible source of the confusion described in post 17.14. In post 19.5, we saw that when… Continue reading 19.6 Cells and batteries

Before you read this, I suggest you read posts 16.33 and 16.39. When iron rusts, it reacts (post 16.33) with oxygen molecules (post 16.30) to form a mixture of iron (II) ions (Fe2+), iron (III) ions (Fe3+) and oxide ions (O2-). To find out more about ions, see post 16.39. The resulting mixture is sometimes… Continue reading 19.5 Oxidation and reduction

We are frequently told about the importance of reading labels on food products to find out exactly what is hidden in them. This is supposed to ensure that we don’t exceed sensible limits for sugar, salt, fat, alcohol or whatever. So, I started by reading the label on a bottle of fizzy mineral water. The… Continue reading 19.4 Dietary information – reading the label