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The Periodic Table 1 of 39 © Boardworks Ltd 2011 2 of 39 © Boardworks Ltd 2011 What is the periodic table? Dmitri Mendeleev created the first modern periodic table. What does it show and why is it always in the same order? 3 of 39 © Boardworks Ltd 2011 What is an element? 4 of 39 © Boardworks Ltd 2011 What is the atomic number? Every element has a unique atomic number (also known as the proton number). This is the number of protons in the nucleus of each atom. electron What is the atomic number of this helium atom? Helium has 2 protons, so its atomic number is 2. Atoms are neutrally charged, so what links atomic number and the number of electrons? proton neutron Atoms are neutrally charged, so the atomic number tells us about the number of electrons in an atom. 5 of 39 © Boardworks Ltd 2011 6 of 39 © Boardworks Ltd 2011 The development of the periodic table 7 of 39 © Boardworks Ltd 2011 How are the elements arranged? 8 of 39 © Boardworks Ltd 2011 The periodic table Arranging all the elements by their atomic number and their properties led to the creation of the periodic table. H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg ? ? ? ? ? ? ? 9 of 39 © Boardworks Ltd 2011 Missing elements! In this periodic table the symbols are replaced by atomic numbers. Some of the numbers are missing – where? 1 3 4 11 12 Two more rows of elements fit here. They are called the lanthanides and actinides. 5 6 2 7 8 9 10 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 10 of 39 © Boardworks Ltd 2011 The elements in the periodic table 11 of 39 © Boardworks Ltd 2011 Columns of elements What are columns of elements called? 1 2 groups 12 of 39 3 4 5 6 7 0 © Boardworks Ltd 2011 Rows of elements What are rows of elements called? periods 1 2 3 4 5 6 7 13 of 39 © Boardworks Ltd 2011 Complete the sentences 14 of 39 © Boardworks Ltd 2011 15 of 39 © Boardworks Ltd 2011 Patterns: metals and non-metals Where are the following different types of elements grouped together in the periodic table? metals on the left and centre non-metals on the right (except hydrogen) semi-metals between metals and non-metals Semi-metals have some properties similar to metals and other properties similar to non-metals. Can you name a semi-metal element? 16 of 39 © Boardworks Ltd 2011 Patterns: physical state Where are elements of different states grouped in the periodic table? solids on the left, in the centre and on the right liquids in the middle and on the right gases on the far right (except hydrogen) Only two elements are liquids at room temperature. What are they? bromine and mercury 17 of 39 © Boardworks Ltd 2011 Metals to non-metals, solids to gases 18 of 39 © Boardworks Ltd 2011 Patterns: reactivity of metals increase in reactivity What happens to the reactivity of metals along a period? What happens to the reactivity of metals down a group? Which is the most reactive metal? Li Be Na Mg Al K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg increase in reactivity 19 of 39 © Boardworks Ltd 2011 Which metal is more reactive? 20 of 39 © Boardworks Ltd 2011 Patterns: reactivity of non-metals Group 0 elements are the most unreactive of all elements. Which is the most reactive non-metal/semi-metal? increase in reactivity increase in reactivity For the remaining non-metals, reactivity increases up a group and along a period from left to right. He B C N O F Ne Si P S Cl Ar Ge As Se Br Kr Sb Te I Xe At Rn unreactive 21 of 39 © Boardworks Ltd 2011 Which non-metal is more reactive? 22 of 39 © Boardworks Ltd 2011 23 of 39 © Boardworks Ltd 2011 Patterns, atomic number and electrons The periodic table shows that patterns in the properties of elements are linked to atomic number. atomic number = number of protons number of protons = number of electrons atomic number = number of electrons Therefore, as atomic number increases by one, the number of electrons also increases by one. This means that the elements in the periodic table are also arranged in order of the number of electrons. 24 of 39 © Boardworks Ltd 2011 How are electrons arranged? Electrons are arranged in shells around an atom’s nucleus. (The shells can also be called energy levels.) Each shell has a maximum number of electrons that it is able to hold. Electrons fill the shells nearest the nucleus first. 1st shell holds a maximum of 2 electrons 2nd shell holds a maximum of 8 electrons 3rd shell holds a maximum of 8 electrons This electron arrangement is written as 2,8,8. 25 of 39 © Boardworks Ltd 2011 Electrons in period 1 Elements in period 1 only have electrons in the first shell. Why are there only two elements in period 1? 1 1 2 3 4 5 6 7 0 H He 1 2 The first shell can hold a maximum of two electrons, so period 1 only includes the elements hydrogen and helium. What is special about the outer shell of helium? 26 of 39 © Boardworks Ltd 2011 Electrons in period 2 Elements in period 2 all have a complete first shell. What happens to electrons in the second shell in period 2? 2 1 2 3 4 5 6 7 0 Li Be B C N O F Ne 2,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8 The second shell is filled across the period from left to right. What is special about the outer shell of neon? 27 of 39 © Boardworks Ltd 2011 Electrons in period 3 Elements in period 3 have complete first and second shells. What happens to electrons in the third shell in period 3? 1 3 2 Na Mg 3 4 5 6 7 0 Al Si P S Cl Ar 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8 2,8,1 2,8,2 2,8,3 The third shell is filled across the period from left to right. What is special about the outer shell of argon? 28 of 39 © Boardworks Ltd 2011 Patterns of electron arrangement Consider the electron arrangements of the first 20 elements in the periodic table. 1 2 3 4 5 6 7 0 2 1 1 2 2,1 2,2 2,3 2,4 2,5 2,6 2,7 3 2,8,1 2,8,2 2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8 4 2,8,8,1 2,8,8,2 2,8 What is the pattern of outer shell electrons in a group? What is the pattern of outer shell electrons across a period? What is the pattern of full electron shells in a group? 29 of 39 © Boardworks Ltd 2011 Electron trends in the periodic table Trends down a group: the number of outer shell electrons is the same the number of complete electron shells increases by one. The number of a group is the same as the number of electrons in the outer shell of elements in that group, except for group 0. Trends across a period: the number of outer shell electrons increases by one the number of complete electron shells stays the same. The point at which a new period starts is the point at which electrons begin to fill a new shell. 30 of 39 © Boardworks Ltd 2011 Electrons and groups 31 of 39 © Boardworks Ltd 2011 Groups and periods 32 of 39 © Boardworks Ltd 2011 What’s the electron arrangement? 33 of 39 © Boardworks Ltd 2011 Names of groups in the periodic table 34 of 39 © Boardworks Ltd 2011 Periodic table and electron structure 35 of 39 © Boardworks Ltd 2011 36 of 39 © Boardworks Ltd 2011 Glossary 37 of 39 © Boardworks Ltd 2011 Anagrams 38 of 39 © Boardworks Ltd 2011 Multiple-choice quiz 39 of 39 © Boardworks Ltd 2011