D. Crowley, 2007

The Periodic Table To recognise the periodic table, and to know what this contains

The Periodic Table

True / False Elements have more than one type of atom Compounds are made up of two or more elements, chemically bound A mixture can contain both elements and compounds Compounds have different properties than the elements they are made from Mixtures are not chemically bound All gases are compounds There are millions of elements False True False

Chemical Symbols What is a chemical symbol Can you identify any? Is there a pattern? Every element has its own chemical symbol It is usually one or two letters long (but can sometimes be three) Every symbol begins with a capital The second and third letters are lower case

Symbols Every element has its own chemical symbol It is usually one or two letters long (but can sometimes be three) Every symbol begins with a capital The second and third letters are lower case MgmgMGmG Examples OoOOoo naNAnANa AGAgagaG

Symbols Sometimes the symbols are really obvious: O = oxygen; Li = lithium; Mg = magnesium However sometimes it is not easy to tell what the symbol stands for (because the symbol come from a name that is not an English word) E.g. W stands for tungsten (from the word wolfram); Na for sodium (from natrium) The chemical symbols are used all over the world, not matter what language people speak

Periodic Table What is the periodic table? What does it show? How is it arranged?

Periodic Table All the different elements are arranged in a chart, called the periodic table The elements are arranged in a special way…

Sorting By the middle of the 19th century about 60 elements were known Scientists looked for ways to sort them - most were metals, but some were non-metals; and most were solid, but a few were gas and some were liquid However it was very difficult to find a pattern!

Mendeleev Then a scientist called Mendeleev did three important steps in helping sort the elements: - He didn’t make a totally regular grid - some rows were longer than others If the elements didn’t fit his table he told the original experimenters that they must have got the mass wrong of the element! He left gaps for elements that he said had not been discovered yet - and predicted what they would be like…

Periodic Table All the different elements are arranged in a chart - the periodic table The elements are arranged so similar elements are found in the vertical columns, called groups The horizontal rows are called periods The metals are on the left, the non-metals on the right

Metals & Non-metals Look at the line that runs down (a bit like some steps) This separates the metals and non-metals (metals on left; non-metals on right) Stick you periodic table into your book Draw the ‘stairs’ to separate the metals and non-metals Colour the periodic table in (showing metals versus non-metals) Stick you periodic table into your book Draw the ‘stairs’ to separate the metals and non-metals Colour the periodic table in (showing metals versus non-metals)

Arrangement Similar elements are placed in groups (there are 8 different groups) Write these groups on your periodic table Note there are some gaps - these are gaps left for undiscovered elements

Size The periodic table shows us one last thing Notice each element has its name and symbol, e.g. oxygen (O) But it also has a number - e.g. Oxygen = 8 O oxygen 8 H hydrogen 1 Mg magnesium 12 Ag silver 47 Pb lead 82 Au gold 79 U uranium 92 Lr lawrencium 103 K potassium 19

Atomic Number This number is the atomic number - it tells you what element is what - e.g. oxygen always has an atomic number of 8, magnesium always has an atomic number of 12 You’ll see in the table that this number gets bigger as you go along it H hydrogen 1 Mg magnesium 12 Ag silver 47 Pb lead 82 Au gold 79 U uranium 92 Lr lawrencium 103 K potassium 19

Summary Each element is made up of one type of atom only All elements are placed in the periodic table The periodic table is split between metals (left) and non-metals (right) Similar elements are placed in groups (there are 8 of them) The rows are called periods

Bingo Take a mini periodic table If an element is said, you have to find its symbol using the big periodic table (on the board) If you have that symbol on your mini periodic table you can colour in the square The winner is the person who gets all their elements coloured in first… E.g. If I said oxygen, you would look it up, discovering its symbol is O If you have the O symbol on your mini periodic table then colour it in!

Periodic Table Song