S3.1 Periodic table (1) - classification of elements
How does the periodic table help us to predict patterns and trends in the properties of elements?The periodic table is probably the perfect example of human ingenuity in Chemistry. What is amazing is that more than 150 years since the periodic table was first proposed by Mendeleev in 1869 there is still not the Periodic Table. If you search in books and on the Internet you will find that there are many different periodic...