The periodic table
All the different elements are arranged in a chart called the A tabular representation of all known elements in order based on atomic number, eg all the noble gases are found on the right of the periodic table.. 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 The number of protons in the nucleus of an atom. Also called the proton number.
- the horizontal rows are called A horizontal row in the periodic table.
- the vertical columns are called A vertical column in the periodic table containing elements with similar chemical properties.
- elements in the same group are similar to each other
The main groups are numbered from 1 to 7 going from left to right, and the last group on the right is group 0. 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 The tendency of a substance to undergo a chemical reaction. metals, and all the elements in group 0 are unreactive non-metals.
The zig-zag line in this diagram separates the Shiny element that is a good conductor of electricity and heat, and which forms basic oxides., on the left, from Element that is a poor conductor of electricity and heat, and which forms acidic oxides., on the right. Hydrogen is a non-metal but it is often put in the middle.
Notice that most elements are metals, rather than non-metals.
Each element has its own chemical symbol, made from letters. Remember that you will only find elements in the periodic table and never compounds. So you won’t find substances like water or copper sulfate in the periodic table.