Chemistry

Two groups of elements Look again at the Periodic Table on page 31. The zig-zag line separates the elements into two groups: metals and non-metals. The non-metals lie to the right of the line, except for hydrogen. As you can see, there are many more metals than non-metals. In fact over 80% of the known elements are metals. What is the difference between them? The metals and non-metals have very different general properties. Look at this table: The properties in the last two rows above are called chemical properties, since they are about chemical change. The others are physical properties. You will find out more about many of those properties later. Exceptions to those properties The properties above are general properties of metals and non-metals. But there are exceptions. For example:  not all metals are hard solids. You can cut sodium and potassium l with a knife, and mercury is a liquid at room temperature.  hydrogen is a non-metal, but forms positive ions (H1) like metals...