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KS4 Chemistry

KS4 Chemistry

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KS4 Chemistry

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  1. KS4 Chemistry The Periodic Table

  2. Contents The Periodic Table Elements and atomic number Arranging elements Patterns of behaviour Electronic structure Teacher resources

  3. What are all substances made of? There are millions of different substances in the world but what are they all made of? Elements the building blocks of all substances. There are about 100 different elements in a variety of forms. From sodium, a reactive metal… …to gold, an unreactive metal. From chlorine, a poisonous gas… …to oxygen, a life-giving gas.

  4. Can you recognise an elementby its properties? You will be given four facts about some everyday substances. For each one, choose the key fact that shows whether or not it is an element.

  5. 1. Is sawdust an element? Facts about sawdust: a) Sawdust is a poor conductor of electricity. b) You make sawdust by breaking wood into very tiny pieces. c) When you heat sawdust, it changes to charcoal and gives off a flammable gas. d) If sawdust is sprinkled on the soil, it slowly rots away. Choose one key fact.

  6. 2. Is oxygen an element? Facts about oxygen: a) Animal life on Earth depends on oxygen. b) Oxygen is a gas that is very difficult to liquefy. c) Whatever chemical tests you try, oxygen never breaks down into other substances. d) When oxygen reacts with carbon, it makes carbon dioxide. Choose one key fact.

  7. 3. Is chalk an element? Facts about chalk: a) When chalk is heated, it changes into lime and carbon dioxide. b) When chalk reacts with acids, it forms carbon dioxide. c) Chalk is a common rock; for example, the white cliffs of Dover are made of chalk. d) Chalk is soft, so it can be used to write with. Choose one key fact.

  8. 4. Is water an element? Facts about water: a) Water is a liquid at room temperature. b) Fish can live in water by breathing dissolved air. c) When you heat water it boils to make steam; when steam is cooled it condenses and makes water again. d) When an electric current passes through water, it splits it up into hydrogen and oxygen. Choose one key fact.

  9. 5. Is salt an element? Facts about salt: a) Salt enhances the flavour of other foods, making it an important cookery ingredient. b) Salt is unusual: it is only slightly more soluble in hot water than in cold water. c) Salt melts at quite a high temperature: 801°C. d) Molten salt changes into sodium and chlorine when an electric current passes through it. Choose one key fact.

  10. Can you recognise an element? In the next section you are not told the names of the substances. For each one, you have to decide: • Whether it is an element. • Which is the key fact. You get a bonus mark for each substance you can name correctly.

  11. 6. Is Substance 1 an element? Facts about Substance 1: a) It is a brown solid that can be polished to a shiny bright finish. b) When heated, it turns black. At 1085°C it melts to a shiny, runny liquid. c) The solid and the liquid are very good conductors of electricity. d) When heated, or when it conducts electricity, it does not break down into other substances. Is Substance 1 an element? Which is the key fact? What is Substance 1?

  12. 7. Is Substance 2 an element? Facts about Substance 2: a) It is a gas at room temperature. b) It is completely unchanged by heat, electricity or other chemical substances. c) It glows blue/green when it conducts electricity in a discharge tube (like a fluorescent light tube). d) About 1% of the Earth’s atmosphere consists of Substance 2. Is Substance 2 an element? Which is the key fact? What is Substance 2?

  13. 8. Is Substance 3 an element? Facts about Substance 3: a) It is a white, crystalline solid that is non-poisonous and has a sweet taste. b) When heated it melts, making a thick brown liquid which bubbles and slowly changes into a black solid. c) Neither the white solid nor the solution conduct electricity. d) It dissolves very well in water. Is Substance 3 an element? Which is the key fact? What is Substance 3?

  14. 9. Is Substance 4 an element? Facts about Substance 4: a) It is a gas at room temperature. b) Below –183°C the gas turns to a liquid. c) The gas is very flammable. d) When it burns, carbon dioxide and water are the only products. Is Substance 4 an element? Which is the key fact? What is Substance 4?

  15. 10. Is Substance 5 an element? Facts about Substance 5: a) It is a solid at room temperature that can exist in several different forms. b) One form is white, catches fire easily and burns vigorously with a spluttering yellow flame. c) Another form is reddish brown, catches fire when strongly heated and burns slowly with a yellow glow. d) Whatever chemical tests you try, none of the forms ever breaks down into other substances. Is Substance 5 an element? Which is the key fact? What is Substance 5?

  16. Properties of elements What is a property of an element? A property is any characteristic of an element. For example, here are some properties of sodium: • metallic • highly reactive • solid but melts easily • feels light (low density) It would be really useful to be able to predict properties of elements instead of having to remember them! Are there any patterns in the properties of elements?

  17. Properties and atomic number Scientists discovered that the properties of elements seemed to depend on atomic number. What is the atomic number of an element? Atoms contain three types of particles: Where are these particles found in an atom?

  18. What is atomic number? What are the particles in this helium atom? neutron electron helium nucleus proton Atomic number = the number of protons in an atom What is the atomic number of helium?

  19. Atomic number andelectrons Atoms of elements contain equal numbers of protons and electrons. How does this affect the charge of such atoms? Atoms of elements have no charge, they are neutral. What is the charge on a fluorine atom? 19 F 9 9 protons 9 electrons 10 neutrons charge = +9 charge = -9 charge = 0 total charge = 0 How are the number of electrons and atomic number related in a neutral atom? They are the same.

  20. Contents The Periodic Table Elements and atomic number Arranging elements Patterns of behaviour Electronic structure Teacher resources

  21. H Mg Al He Li Be B C N O F Ne Na Si P S Cl Ar K Atomic number and patterns When scientists arranged elements in order of increasing atomic number they found patterns in their properties. reactive gases reactive metals unreactive gases

  22. He Li Be B C N O F Ne Na Si P S Cl Ar K H Mg Al 2 3 4 5 6 7 8 9 10 11 14 15 16 17 18 19 1 12 13 Positions of similar elements Compare the positions of similar elements. reactive gases reactive metals How many elements are there from one reactive gas to the next? 8 How many elements are there from one reactive metal to the next? 8

  23. He Li Be B C N O F Ne Na Si P S Cl Ar K H Mg Al 2 3 4 5 6 7 8 9 10 11 14 15 16 17 18 19 1 12 13 H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar Arranging elements Divide the elements at set intervals, arrange them according to their properties and what patterns do you see? cut here cut here cut here Arranging these strips in rows… K

  24. Ne F B N O Li Be C Al Mg Si P S Cl Ar Na Arranging elements When elements are arranged according to their properties what patterns do you see and what element is missing? hydrogen is a special case H He K reactive metals reactive gases unreactive gases Similar elements go into the same columns. Hydrogen is an exception. This reactive gas is best positioned above the reactive metals.

  25. 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 ? ? ? The periodic table Arranging all the elements by atomic number and properties led to the creation of… the periodic table

  26. Group number 1 2 0 3 5 6 7 4 transition elements Columns of elements What are columns of elements called? Groups 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 ? ? ?

  27. 1 2 3 4 5 6 7 Rows of elements What are rows of elements called? Periods Period number 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 ? ? ?

  28. Name the position What is the Group and Period of this element? C K Cl Mg Group 2 Period 3 Group 1 Period 4 Period 2 Group 4 Group 7 Period 3 1 2 0 3 5 6 7 4 H 1 He B C N O F Ne C Li Be 2 Mg Na Mg Al Si P S Cl Cl Ar 3 K K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 4 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 5 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 6 Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ? 7

  29. 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 26 19 20 21 22 23 24 25 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 Missing elements! In this periodic table the symbols are replaced by atomic numbers. Some of the numbers are missing – where? Two more periods of elements fit here but are only shown on some periodic tables. These are called the lanthanides and actinides. 1 H He B C N O F Ne Li Be 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 ? ? ?

  30. Contents The Periodic Table Elements and atomic number Arranging elements Patterns of behaviour Electronic structure Teacher resources

  31. Patterns 1: Metals and non-metals Where are different types of elements grouped together on the periodic table? on the left and centre metals non-metals mostly on the right metalloids in between metals and non-metals Metalloids aren’t type of rock music fan! Metalloids actually have some properties similar to metals and other properties similar to no-metals. Can you name a metalloid element?

  32. Metals, non-metals and metalloids

  33. 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 ? ? ? Metal, non-metal or metalloid? Is this element a metal, non-metal or metalloid? metal francium (Fr) krypton (Kr) scandium (Sc) metalloid cobalt (Co) silicon (Si) metal metal non-metal Si Kr Sc Co Fr

  34. Patterns 2: Physical state Where are elements of different states grouped together on the periodic table? solids on the left, in the centre and to the right liquids only two elements are liquid gases mostly on the far right Only two elements are liquids at room temperature. Can you name these two elements? mercury bromine

  35. Physical state

  36. 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 ? ? ? Solid, liquid or gas? Is this element a solid, liquid or gas at room temperature? krypton (Kr) bromine (Br) nitrogen (N) barium (Ba) niobium (Nb) solid solid gas gas liquid N Br Kr Nb Ba

  37. H Li Be Na Mg Al K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb 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 ? ? ? Patterns 3: Reactivity of metals What happens the reactivity of metals along a period? What happens the reactivity of metals down a group? Which is the most reactive metal? morereactive more reactive

  38. H Li Be Na Mg Al K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb 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 ? ? ? Which metal is more reactive? From the positions of these metals in the periodic table, which metal in each pair is the more reactive? calcium (Ca) or magnesium (Mg) copper (Cu) or barium (Ba) potassium (K) or lithium (Li) calcium (Ca) or iron (Fe)

  39. Patterns 4: Reactivity of non-metals What are the rules for the reactivity of the non-metals? 1. Group 0 is the most unreactive group of elements. 2. For the remaining non-metals, reactivity increases to the right of a period and up a group. more reactive He u n reactive B C N O F Ne Si P S Cl Ar more reactive As Se Br Kr Te I Xe At Rn Which is the most reactive non-metal?

  40. Which non-metal is more reactive? From the positions of these non-metals in the periodic table, which non-metal in the pair is the more reactive? oxygen (O) or silicon (Si) neon (Ne) or iodine (I) fluorine (F) or chlorine (Cl) carbon (C) or oxygen (O) He B C N O F Ne Si P S Cl Ar As Se Br Kr Te I Xe At Rn

  41. Contents The Periodic Table Elements and atomic number Arranging elements Patterns of behaviour Electronic structure Teacherresources

  42. 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 ? ? ? Patterns and atomic number The periodic table shows that patterns in the properties of elements are linked to atomic number. What links atomic number and the properties of elements? electrons

  43. ATOMS All atoms of the same element have the same proton number. Elements 1–20 5B 8O 20Ca 15P 18Ar 14Si 11Na 2He 7N 13Al 12Mg 19K 1H 6C 4Be 3Li 9F 16S 10Ne 17Cl Number of electrons = number of protons (unless the atom is charged).

  44. INSIDE AN ATOM The nucleus contains almost the entire mass of the atom. Tiny electrons whizz around the nucleus. Almost all of the atom is empty space. The size of the nucleus compared with the size of the atom is like ‘the size of a man’s fist compared with the dome of St Paul’s Cathedral’(Rutherford).

  45. ELECTRONS Electrons can’t just go anywhere. They move in spaces called orbitals. Orbitals have complicated shapes which are represented by the circles. The further away they are from the nucleus, the higher the energy of the electrons. nucleus electron Diagram not to scale.

  46. ENERGY LEVELS ON A HILLSIDE Increasing energy This stone has most energy because it has furthest to fall. These stones have least energy because they are nearest the bottom. Each different height from the ground is an ENERGY LEVEL. Stones must be at one level or another, not in between. Part of a hill

  47. ENERGY LEVELS AROUND THE NUCLEUS OF AN ATOM Increasing energy 32 Level 4 18 Level 3 8 Level 2 The further away you move from the nucleus, the more orbitals available, but they are of higher energy. Level 1 2 Nucleus Figures in red show maximum number of electrons in each energy level.

  48. ARRANGEMENT OF ELECTRONS IN A HYDROGEN ATOM: 1H Energy 32 Level 4 18 Level 3 The electron occupies the lowest available energy level. 8 Level 2 Level 1  2 Electronic configuration: 1. Nucleus

  49. ARRANGEMENT OF ELECTRONS IN A HELIUM ATOM: 2He Energy 32 Level 4 18 Level 3 The electron occupies the lowest available energy level. 8 Level 2 Level 1   2 Electronic configuration: 2. Nucleus

  50. ARRANGEMENT OF ELECTRONS IN A LITHIUM ATOM: 3Li Energy 32 Level 4 18 Level 3 The new electron occupies the lowest available energy level.  8 Level 2 Level 1   2  filled orbital most recently filled orbital  Electronic configuration: 2, 1. Nucleus