1. The Periodic Table Noadswood Science, 2013

2. The Periodic Table To understand what is meant by an atom and an element, and how they are represented in the periodic table Friday, September 30, 2016

3. 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! There were two obvious ways to categories the elements: their physical / chemical properties and their relative atomic mass…

4. Newlands Newlands arranged known elements in 1864 – he notices every 8 th element had similar properties so he listed the known elements in rows of 7 These were known as Newland’s Octaves – however the pattern broken down when he got to the transition metals (as he left no gaps)

5. Newlands Criticised Newlands arrangement was criticised because: - 1.His groups contained elements which did not have similar properties, such as carbon and titanium 2.He mixed up the metals and non-metals, such as oxygen and iron 3.He did not leave any gaps for undiscovered elements

6. Mendeleev Then a scientist called Mendeleev did three important steps in helping sort the elements in 1869: - 1.He didn’t make a totally regular grid - some rows were longer than others 2.If the elements didn’t fit his table he told the original experimenters that they must have got the mass wrong of the element! 3.He left gaps for elements that he said had not been discovered yet - and predicted what they would be like…

7. Mendeleev Mendeleev’s table of elements and the gaps allowed for predictions to be made for the properties of undiscovered elements…

8. Periodic Table What is the periodic table and what does it show? There are over 100 different elements, arranged in a chart called the periodic table – the elements are arranged in order of atomic mass (proton number)

9. Modern Periodic Table The modern Periodic Table can be viewed as an arrangement of elements in terms of their electronic structures Elements in the same group have the same number of electrons in their highest occupied energy level (outer shell)

10. Chemical 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 Examples Mg MGmG naNAnANa OoOOoo AGAgagaG

11. Chemical 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

12. Periodic Table Stick your periodic table in your book – for your exam it will be necessary to learn the first 20 elements + some common elements including: lead (Pb), copper (Cu), zinc (Zn) etc…

13. Decode The Hidden Message See if you can write your name using the elements within the Periodic Table…

14. Decode The Hidden Message Can you identify the hidden messages in the following: - Carbon, Radon, Carbon, Potassium Thorium, Einsteinium (take away the s) Sulfur, Yttrium, Manganese (take away the n), Boron, Oxygen, Lithium (take away the i), Sulfur Oxygen, Nitrogen Thorium, Einsteinium (take away the s) Phosphorus, Iron (take away the f), Argon (take away the a), Iodine, Oxygen, Cadmium (take away the c), Iodine, Carbon Titanium (take away the i), Aluminium (take away the l), Boron, Lithium (take away the i), Iron (take away the f) Oxygen, Fluorine Neon (take away the n), Chlorine (take away the c), Germanium (take away the g), Manganese (take away the n), Germanium (take away the g), Nitrogen, Tellurium (take away the e), Sulfur

15. Decode The Hidden Message Can you identify the hidden messages in the following: - Carbon, Radon, Carbon, Potassium CRACK Thorium, Einsteinium (take away the s) THE Sulfur, Yttrium, Manganese (take away the n), Boron, Oxygen, Lithium (take away the i), Sulfur SYMBOLS Oxygen, Nitrogen ON Thorium, Einsteinium (take away the s) THE Phosphorus, Iron (take away the f), Argon (take away the a), Iodine, Oxygen, Cadmium (take away the c), Iodine, Carbon PERIODIC Titanium (take away the i), Aluminium (take away the l), Boron, Lithium (take away the i), Iron (take away the f) TABLE Oxygen, Fluorine OF Neon (take away the n), Chlorine (take away the c), Germanium (take away the g), Manganese (take away the n), Germanium (take away the g), Nitrogen, Tellurium (take away the e), Sulfur ELEMENTS

16. Periodic Table Arrangement The vertical columns in the periodic table are called groups – each group contains elements that have similar properties The periodic table has eight main groups, e.g. group 1 contains very reactive metals such as sodium (Na) and potassium (K) whilst group 7 contains very reactive non- metals such as chlorine (Cl) and bromine (Br) The horizontal rows are called periods (each new period represents another full shell of electrons) The metals are on the left, the non-metals on the right

17. Periodic Table Alkali Metals Alkaline Earth Metals Transition Metals Halogens Noble Gases

18. Periodic Table Visually Visual Elements

19. Periodic Table Visually