What can the modern periodic table tell us? C3 The Periodic Table Lessons 1-5 What can the modern periodic table tell us? Starter: On the periodic table in front of you, annotate everything you know about what it tells you. e.g. Group 1 = alkali metals. Think about – order of reactivity, names of groups/sections, what the numbers tell you about atoms, what the symbols tell you, size of atoms…. Etc. Displacement reaction demo, Alkali metals demo – periodic table sheets on A3, fact sheets a4 back to back.

Glossary Element – a substance made of 1 type of atom that cannot be broken down into anything chemically simpler. Periodic table – an arrangement of elements in the order of their atomic numbers, forming groups and periods.

Who made it and how? The old periodic table was rubbish – it was poorly ordered (based on patterns of behaviour, then on mass) and made little sense. In 1964 Newlands attempted to put it in a sensible order by mass and saw similarities between every 8th element . Mendeleev ordered the elements based on their atomic weights and arranged them so there was a pattern. He left GAPS because he predicted new elements would fit in, as they were discovered. He was right!

The Modern Periodic Table Protons and neutrons were discovered in the 20th century. Elements are now arranged in terms of proton number. They increase by 1 each time. Check out the PT! It could also be seen as being arranged in terms of electronic structure. Within a group elements have similar properties. Check out the alkali metals.

To Recap 1) What does an atom look like? 2) what do the numbers mean? 3) What is the electronic structure?

Labels to include Group 1-8 Name Alkali metals, (reactive metals – group 1 and 2) Halogens, Nobel gases. Number of electrons in outer shells Metals and non metals Transition metals Draw electron shells for group 1 and 7

Properties of some elements Use the worksheet and the pages noted to make a fact sheet about the properties of the alkali metals, transition metals and halogens.

Other Things of Interest http://www.youtube.com/watch?v=Mx5JJWI2aaw Reaction of alkali metals and Halogens

1) Displacement reactions of halogens A more reactive halogen will displace a less reactive one from solutions. e.g. Chlorine + potassium bromide  potassium chloride + bromine. Chlorine is MORE reactive that bromine so boots it out of the way.

Complete the following with either the correct chemicals or “no reaction”. Fluorine + potassium chloride  Bromine + sodium chloride  Iodine + lithium bromide  Chlorine + ……………………  potassium fluoride + ……………