Really enjoyed the book. Would give it 5 stars even though a bit over head in comprehension. My gripe - when mentioning an element why couldn't they add the symbol/abbreviation in the text, like they do in the index. When wanting to check its location on the periodical chart, one has to go to the Index first to get the symbol, then go to the chart. Frustrating. If this was done I would surely have remembered many more of the symbols by the end of the book. The elements number would be handy too, so one doesn't have to search so much. It would also be nice for them to list the elements and give a brief description, such as gas, metal, radioactive, poisonous, rare, used in cell phones or no known use, unstable.... Granted a book could be written just on those items, but it would help to grasp the inter-related aspects of the elements of the chart.