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Introduction

• There are more than 100 different elements. The periodic table is a chart showing all the elements arranged in a particular way. A Russian scientist called Dmitri
• Mendeleev produced one of the first practical periodic tables in the
• 19th century. The modern periodic table is based closely on the ideas he
• used:
• the elements are arranged in order of increasing atomic number
• the horizontal rows are called periods
• the vertical columns are called groups
• elements in the same group have similar properties/are similar to each other.

A Picture Of The Periodic Table

• 
• Legenda: The Modern Periodic Table

Description Of The Periodic Table

• The main groups are numbered from 1 to 7 going from left to right, and
• the last group on the right is group 0.
• Each element has its own chemical symbol, made from letters.
• Note
• that you will never find a compound in the periodic table, because
• these consist of two or more different elements joined together by
• chemical bonds.
• So you won’t find substances like water or copper sulfate in the periodic table.
• The section in the middle of the
• table is called the Transition Metals. You may also see all
• the groups numbered (including the transition metals), this time from 1
• to 18. If you know what one of the elements in a group is like, you can
• make predictions about the other elements in a group. For example, all
• the elements in group 1 are reactive metals, and all the elements in group 0 are non-reactive non-metals.
• Hydrogen is a non-metal but it is often put in the middle.
• Notice that most elements are metals, rather than non-metals.