1. Essential Natural Science 1 Atoms and elements CONTENTS RESOURCES ACTIVITY LINKS HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK

2. Contents Atoms and elements Atoms History and characteristics The Periodic Table Organisation Chemical formulas Molecules and crystals Elements found in nature Hydrogen Helium Nitrogen Oxygen Carbon In the Earth's crust In sea water HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK HOME

3. Resources HOME History and characteristics of atoms How are elements classified? How are atoms organised? What is a chemical formula? Hydrogen Nitrogen Helium Oxygen Carbon Elements in the Earth's crust Elements in sea water HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK Activity: Atoms and elements Links

4. History and characteristics of atoms 400 BC 19th century Present Democritus Atomic theory: Matter is made up of tiny, indivisible units called atoms. Atom comes from a Greek word, which means “ not divisible” . John Dalton Matter is made up of indivisible atoms. Each element is made up of identical atoms. Atoms combine to form compounds of two or more different elements. Atoms are made up of smaller particles. electrons neutrons protons HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK

5. How are elements classified? 1 2 3 4 5 7 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 The Periodic Table of Elements LANTHANIDES ACTINIDES Al Aluminium 13 B Boron 5 Si Silicon 14 C Carbon 6 As Arsenic 33 P Phosphorus 15 N Nitrogen 7 Po Polonium 84 Te Tellurium 52 Se Selenium 34 S Sulphur 16 O Oxygen 8 At Astatine 85 I Iodine 53 Br Bromine 35 Cl Chlorine 17 F Fluorine 9 He Helium 2 Rn Radon 86 Xe Xenon 54 Kr Krypton 36 Ar Argon 18 Ne Neon 10 H Hydrogen 1 Lr Lawrencium 103 No Nobelium 102 Md Mendelevium 101 Fm Fermium 100 Es Einsteinium 99 Cf Californium 98 Bk Berkelium 97 Cm Curium 96 Am Americium 95 Pu Plutonium 94 Np Neptunium 93 U Uranium 92 Pa Protactinium 91 Th Thorium 90 Lu Lutetium 71 Yb Ytterbium 70 Tm Thulium 69 Er Erbium 68 Ho Holmium 67 Dy Dyprosium 66 Tb Terbium 65 Gd Gadolinium 64 Eu Europium 63 Sm Samarium 62 Pm Promethium 61 Nd Neodymium 60 Pr Praseodymium 59 Ce Cerium 58 Rg Roentgenium 111 Ds Darmstadtium 110 Mt Meitnerium 109 Hs Hassium 108 Bh Bohrium 107 Sg Seaborgium 106 Db Dubnium 105 Rf Rutherfordium 104 Ac Actinium 89 Ra Radium 88 Cs Cesium 55 Bi Bismuth 83 Pb Lead 82 Ti Thallium 81 Hg Mercury 80 Au Gold 79 Pt Platinum 78 Ir Iridium 77 Os Osmium 76 Re Rhenium 75 W Tungsten 74 Ta Tantalum 73 Hf Hafnium 72 La Lanthanum 57 Ba Barium 56 Sb Antimony 51 Sn Tin 50 In Indium 49 Cd Cadmium 48 Ag Silver 47 Pd Palladium 46 Rh Rhodium 45 Ru Ruthenium 44 Tc Technetium 43 Mo Molybdenum 42 Nb Niobium 41 Zr Zirconium 40 Y Yttrium 39 Sr Strontium 38 Ge Germanium 32 Ga Gallium 31 Zn Zinc 30 Cu Copper 29 Ni Níckel 28 Co Cobalt 27 Fe Iron 26 Mn Manganese 25 Cr Chromium 24 V Vanadium 23 Ti Titanium 22 Sc Scandium 21 Ca Calcium 20 Mg Magnesium 12 Fr Francium 87 Rb Rubidium 37 K Potassium 19 Na Sodium 11 Be Beryllium 4 Li Lithium 3 6 7 CLICK ON GREEN BUTTONS TO LEARN MORE HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK

6. How are elements classified? 1 2 3 4 5 7 6 Elements with similar chemical properties Vertical column or GROUP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 LANTHANIDES ACTINIDES Al Aluminium 13 B Boron 5 Si Silicon 14 C Carbon 6 As Arsenic 33 P Phosphorus 15 N Nitrogen 7 Po Polonium 84 Te Tellurium 52 Se Selenium 34 S Sulphur 16 O Oxygen 8 At Astatine 85 I Iodine 53 Br Bromine 35 Cl Chlorine 17 F Fluorine 9 He Helium 2 Rn Radon 86 Xe Xenon 54 Kr Krypton 36 Ar Argon 18 Ne Neon 10 H Hydrogen 1 Lr Lawrencium 103 No Nobelium 102 Md Mendelevium 101 Fm Fermium 100 Es Einsteinium 99 Cf Californium 98 Bk Berkelium 97 Cm Curium 96 Am Americium 95 Pu Plutonium 94 Np Neptunium 93 U Uranium 92 Pa Protactinium 91 Th Thorium 90 Lu Lutetium 71 Yb Ytterbium 70 Tm Thulium 69 Er Erbium 68 Ho Holmium 67 Dy Dyprosium 66 Tb Terbium 65 Gd Gadolinium 64 Eu Europium 63 Sm Samarium 62 Pm Promethium 61 Nd Neodymium 60 Pr Praseodymium 59 Ce Cerium 58 Rg Roentgenium 111 Ds Darmstadtium 110 Mt Meitnerium 109 Hs Hassium 108 Bh Bohrium 107 Sg Seaborgium 106 Db Dubnium 105 Rf Rutherfordium 104 Ac Actinium 89 Ra Radium 88 Cs Cesium 55 Bi Bismuth 83 Pb Lead 82 Ti Thallium 81 Hg Mercury 80 Au Gold 79 Pt Platinum 78 Ir Iridium 77 Os Osmium 76 Re Rhenium 75 W Tungsten 74 Ta Tantalum 73 Hf Hafnium 72 La Lanthanum 57 Ba Barium 56 Sb Antimony 51 Sn Tin 50 In Indium 49 Cd Cadmium 48 Ag Silver 47 Pd Palladium 46 Rh Rhodium 45 Ru Ruthenium 44 Tc Technetium 43 Mo Molybdenum 42 Nb Niobium 41 Zr Zirconium 40 Y Yttrium 39 Sr Strontium 38 Ge Germanium 32 Ga Gallium 31 Zn Zinc 30 Cu Copper 29 Ni Nickel 28 Co Cobalt 27 Fe Iron 26 Mn Manganese 25 Cr Chromium 24 V Vanadium 23 Ti Titanium 22 Sc Scandium 21 Ca Calcium 20 Mg Magnesium 12 Fr Francium 87 Rb Rubidium 37 K Potassium 19 Na Sodium 11 Be Beryllium 4 Li Lithium 3 6 7 ROW GO BACK HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK

7. How are elements classified? 1 2 3 4 5 7 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 atomic symbol name of the element LANTHANIDES ACTINIDES Al Aluminium 13 B Boron 5 Si Silicon 14 C Carbon 6 As Arsenic 33 P Phosphorus 15 N Nitrogen 7 Po Polonium 84 Te Tellurium 52 Se Selenium 34 S Sulphur 16 O Oxygen 8 At Astatine 85 I Iodine 53 Br Bromine 35 Cl Chlorine 17 F Fluorine 9 He Helium 2 Rn Radon 86 Xe Xenon 54 Kr Krypton 36 Ar Argon 18 Ne Neon 10 H Hydrogen 1 Lr Lawrencium 103 No Nobelium 102 Md Mendelevium 101 Fm Fermium 100 Es Einsteinium 99 Cf Californium 98 Bk Berkelium 97 Cm Curium 96 Am Americium 95 Pu Plutonium 94 Np Neptunium 93 U Uranium 92 Pa Protactinium 91 Th Thorium 90 Lu Lutetium 71 Yb Ytterbium 70 Tm Thulium 69 Er Erbium 68 Ho Holmium 67 Dy Dyprosium 66 Tb Terbium 65 Gd Gadolinium 64 Eu Europium 63 Sm Samarium 62 Pm Promethium 61 Nd Neodymium 60 Pr Praseodymium 59 Ce Cerium 58 Rg Roentgenium 111 Ds Darmstadtium 110 Mt Meitnerium 109 Hs Hassium 108 Bh Bohrium 107 Sg Seaborgium 106 Db Dubnium 105 Rf Rutherfordium 104 Ac Actinium 89 Ra Radium 88 Cs Cesium 55 Bi Bismuth 83 Pb Lead 82 Ti Thallium 81 Hg Mercury 80 Au Gold 79 Pt Platinum 78 Ir Iridium 77 Os Osmium 76 Re Rhenium 75 W Tungsten 74 Ta Tantalum 73 Hf Hafnium 72 La Lanthanum 57 Ba Barium 56 Sb Antimony 51 Sn Tin 50 In Indium 49 Cd Cadmium 48 Ag Silver 47 Pd Palladium 46 Rh Rhodium 45 Ru Ruthenium 44 Tc Technetium 43 Mo Molybdenum 42 Nb Niobium 41 Zr Zirconium 40 Y Yttrium 39 Sr Strontium 38 Ge Germanium 32 Ga Gallium 31 Zn Zinc 30 Cu Copper 29 Ni Nickel 28 Co Cobalt 27 Fe Iron 26 Mn Manganese 25 Cr Chromium 24 V Vanadium 23 Ti Titanium 22 Sc Scandium 21 Ca Calcium 20 Mg Magnesium 12 Fr Francium 87 Rb Rubidium 37 K Potassium 19 Na Sodium 11 Be Beryllium 4 Li Lithium 3 6 7 H Hydrogen HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK GO BACK

8. It has six protons. atomic number How are elements classified? 1 2 3 4 5 7 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 carbon atom LANTHANIDES ACTINIDES Al Aluminium 13 B Boron 5 Si Silicon 14 C Carbon 6 As Arsenic 33 P Phosphorus 15 N Nitrogen 7 Po Polonium 84 Te Tellurium 52 Se Selenium 34 S Sulphur 16 O Oxygen 8 At Astatine 85 I Iodine 53 Br Bromine 35 Cl Chlorine 17 F Fluorine 9 He Helium 2 Rn Radon 86 Xe Xenon 54 Kr Krypton 36 Ar Argon 18 Ne Neon 10 H Hydrogen 1 Lr Lawrencium 103 No Nobelium 102 Md Mendelevium 101 Fm Fermium 100 Es Einsteinium 99 Cf Californium 98 Bk Berkelium 97 Cm Curium 96 Am Americium 95 Pu Plutonium 94 Np Neptunium 93 U Uranium 92 Pa Protactinium 91 Th Thorium 90 Lu Lutetium 71 Yb Ytterbium 70 Tm Thulium 69 Er Erbium 68 Ho Holmium 67 Dy Dyprosium 66 Tb Terbium 65 Gd Gadolinium 64 Eu Europium 63 Sm Samarium 62 Pm Promethium 61 Nd Neodymium 60 Pr Praseodymium 59 Ce Cerium 58 Rg Roentgenium 111 Ds Darmstadtium 110 Mt Meitnerium 109 Hs Hassium 108 Bh Bohrium 107 Sg Seaborgium 106 Db Dubnium 105 Rf Rutherfordium 104 Ac Actinium 89 Ra Radium 88 Cs Cesium 55 Bi Bismuth 83 Pb Lead 82 Ti Thallium 81 Hg Mercury 80 Au Gold 79 Pt Platinum 78 Ir Iridium 77 Os Osmium 76 Re Rhenium 75 W Tungsten 74 Ta Tantalum 73 Hf Hafnium 72 La Lanthanum 57 Ba Barium 56 Sb Antimony 51 Sn Tin 50 In Indium 49 Cd Cadmium 48 Ag Silver 47 Pd Palladium 46 Rh Rhodium 45 Ru Ruthenium 44 Tc Technetium 43 Mo Molybdenum 42 Nb Niobium 41 Zr Zirconium 40 Y Yttrium 39 Sr Strontium 38 Ge Germanium 32 Ga Gallium 31 Zn Zinc 30 Cu Copper 29 Ni Nickel 28 Co Cobalt 27 Fe Iron 26 Mn Manganese 25 Cr Chromium 24 V Vanadium 23 Ti Titanium 22 Sc Scandium 21 Ca Calcium 20 Mg Magnesium 12 Fr Francium 87 Rb Rubidium 37 K Potassium 19 Na Sodium 11 Be Beryllium 4 Li Lithium 3 6 7 C Carbon 6 HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK GO BACK

9. It has seven protons. atomic number nitrogen atom How are elements classified? 1 2 3 4 5 7 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 LANTHANIDES ACTINIDES Al Aluminium 13 B Boron 5 Si Silicon 14 C Carbon 6 As Arsenic 33 P Phosphorus 15 N Nitrogen 7 Po Polonium 84 Te Tellurium 52 Se Selenium 34 S Sulphur 16 O Oxygen 8 At Astatine 85 I Iodine 53 Br Bromine 35 Cl Chlorine 17 F Fluorine 9 He Helium 2 Rn Radon 86 Xe Xenon 54 Kr Krypton 36 Ar Argon 18 Ne Neon 10 H Hydrogen 1 Lr Lawrencium 103 No Nobelium 102 Md Mendelevium 101 Fm Fermium 100 Es Einsteinium 99 Cf Californium 98 Bk Berkelium 97 Cm Curium 96 Am Americium 95 Pu Plutonium 94 Np Neptunium 93 U Uranium 92 Pa Protactinium 91 Th Thorium 90 Lu Lutetium 71 Yb Ytterbium 70 Tm Thulium 69 Er Erbium 68 Ho Holmium 67 Dy Dyprosium 66 Tb Terbium 65 Gd Gadolinium 64 Eu Europium 63 Sm Samarium 62 Pm Promethium 61 Nd Neodymium 60 Pr Praseodymium 59 Ce Cerium 58 Rg Roentgenium 111 Ds Darmstadtium 110 Mt Meitnerium 109 Hs Hassium 108 Bh Bohrium 107 Sg Seaborgium 106 Db Dubnium 105 Rf Rutherfordium 104 Ac Actinium 89 Ra Radium 88 Cs Cesium 55 Bi Bismuth 83 Pb Lead 82 Ti Thallium 81 Hg Mercury 80 Au Gold 79 Pt Platinum 78 Ir Iridium 77 Os Osmium 76 Re Rhenium 75 W Tungsten 74 Ta Tantalum 73 Hf Hafnium 72 La Lanthanum 57 Ba Barium 56 Sb Antimony 51 Sn Tin 50 In Indium 49 Cd Cadmium 48 Ag Silver 47 Pd Palladium 46 Rh Rhodium 45 Ru Ruthenium 44 Tc Technetium 43 Mo Molybdenum 42 Nb Niobium 41 Zr Zirconium 40 Y Yttrium 39 Sr Strontium 38 Ge Germanium 32 Ga Gallium 31 Zn Zinc 30 Cu Copper 29 Ni Nickel 28 Co Cobalt 27 Fe Iron 26 Mn Manganese 25 Cr Chromium 24 V Vanadium 23 Ti Titanium 22 Sc Scandium 21 Ca Calcium 20 Mg Magnesium 12 Fr Francium 87 Rb Rubidium 37 K Potassium 19 Na Sodium 11 Be Beryllium 4 Li Lithium 3 6 7 N Nitrogen 7 HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK GO BACK

10. How are elements classified? 1 2 3 4 5 7 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 blue: liquid black: solid red: gas purple: man-made LANTHANIDES ACTINIDES Al Aluminium 13 B Boron 5 Si Silicon 14 C Carbon 6 As Arsenic 33 P Phosphorus 15 N Nitrogen 7 Po Polonium 84 Te Tellurium 52 Se Selenium 34 S Sulphur 16 O Oxygen 8 At Astatine 85 I Iodine 53 Br Bromine 35 Cl Chlorine 17 F Fluorine 9 He Helium 2 Rn Radon 86 Xe Xenon 54 Kr Krypton 36 Ar Argon 18 Ne Neon 10 H Hydrogen 1 Lr Lawrencium 103 No Nobelium 102 Md Mendelevium 101 Fm Fermium 100 Es Einsteinium 99 Cf Californium 98 Bk Berkelium 97 Cm Curium 96 Am Americium 95 Pu Plutonium 94 Np Neptunium 93 U Uranium 92 Pa Protactinium 91 Th Thorium 90 Lu Lutetium 71 Yb Ytterbium 70 Tm Thulium 69 Er Erbium 68 Ho Holmium 67 Dy Dyprosium 66 Tb Terbium 65 Gd Gadolinium 64 Eu Europium 63 Sm Samarium 62 Pm Promethium 61 Nd Neodymium 60 Pr Praseodymium 59 Ce Cerium 58 Rg Roentgenium 111 Ds Darmstadtium 110 Mt Meitnerium 109 Hs Hassium 108 Bh Bohrium 107 Sg Seaborgium 106 Db Dubnium 105 Rf Rutherfordium 104 Ac Actinium 89 Ra Radium 88 Cs Cesium 55 Bi Bismuth 83 Pb Lead 82 Ti Thallium 81 Hg Mercury 80 Au Gold 79 Pt Platinum 78 Ir Iridium 77 Os Osmium 76 Re Rhenium 75 W Tungsten 74 Ta Tantalum 73 Hf Hafnium 72 La Lanthanum 57 Ba Barium 56 Sb Antimony 51 Sn Tin 50 In Indium 49 Cd Cadmium 48 Ag Silver 47 Pd Palladium 46 Rh Rhodium 45 Ru Ruthenium 44 Tc Technetium 43 Mo Molybdenum 42 Nb Niobium 41 Zr Zirconium 40 Y Yttrium 39 Sr Strontium 38 Ge Germanium 32 Ga Gallium 31 Zn Zinc 30 Cu Copper 29 Ni Nickel 28 Co Cobalt 27 Fe Iron 26 Mn Manganese 25 Cr Chromium 24 V Vanadium 23 Ti Titanium 22 Sc Scandium 21 Ca Calcium 20 Mg Magnesium 12 Fr Francium 87 Rb Rubidium 37 K Potassium 19 Na Sodium 11 Be Beryllium 4 Li Lithium 3 6 7 Hg Mercury 80 HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK GO BACK

11. How are atoms organised? Single atoms Molecules Crystals Simple molecules Compound molecules Simple crystals Compound crystals noble gases HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK helium (He) oxygen (O 2 ) water (H 2 O) diamond (carbon) salt (sodium and chlorine)

12. How are atoms organised? Single atoms Molecules Crystals Simple molecules Compound molecules Simple crystals Compound crystals noble gases helium (He) HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK oxygen (O 2 ) water (H 2 O) diamond (carbon) salt (sodium and chlorine)

13. How are atoms organised? Single atoms Molecules Crystals Simple molecules Compound molecules Simple crystals Compound crystals noble gases oxygen (O 2 ) HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK helium (He) water (H 2 O) diamond (carbon) salt (sodium and chlorine)

14. How are atoms organised? Single atoms Molecules Crystals Simple molecules Compound molecules Simple crystals Compound crystals noble gases water (H 2 O) HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK helium (He) oxygen (O 2 ) diamond (carbon) salt (sodium and chlorine)

15. How are atoms organised? Single atoms Molecules Crystals Simple molecules Compound molecules Simple crystals Compound crystals noble gases diamond (carbon) HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK helium (He) oxygen (O 2 ) water (H 2 O) salt (sodium and chlorine)

16. How are atoms organised? Single atoms Molecules Crystals Simple molecules Compound molecules Simple crystals Compound crystals noble gases salt (sodium and chlorine) HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK helium (He) oxygen (O 2 ) water (H 2 O) diamond (carbon)

17. Crystals Molecules What is a chemical formula? A representation of the elements in a substance HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK Simple substances Compound substances Crystals Compound crystals

18. Crystals Molecules What is a chemical formula? A representation of the elements in a substance Simple substance oxygen molecule 2 oxygen atoms O 2 symbol for the element number of atoms HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK Simple substances Crystals Compound crystals Compound substances

19. Crystals Molecules What is a chemical formula? A representation of the elements in a substance Compound substance water molecule 1 oxygen atom 2 hydrogen atoms symbols for each element number of atoms H 2 O HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK Compound substances Crystals Compound crystals Simple substances

20. Crystals Molecules What is a chemical formula? A representation of the elements in a substance Element carbon carbon atoms symbol for the element The chemical formula is the same as the chemical symbol. C HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK Crystals Compound crystals Simple substances Compound substances

21. Crystals Molecules What is a chemical formula? A representation of the elements in a substance NaCl Compound crystals symbols for the elements sodium chloride chlorine atom sodium atom proportion of each HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK Compound crystals Crystals Simple substances Compound substances

27. 2.2 % Elements in the Earth's crust 3.5 % 4.5 % 7.9 % Aluminium Iron Calcium Magnesium 28 % Silicon 47 % Oxygen (O) 28 % Silicon (Si) 7.9 % Aluminium (Al) 4.5 % Iron (Fe) 3.5 % Calcium (Ca) 2.5 % Sodium (Na) 2.5 % Potassium (K) 2.2 % Magnesium (Mg) CLICK ON THE GREEN BUTTONS TO LEARN MORE HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK

33. Elements in sea water HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK composition of sea water characteristics of water Chlorine Sodium Potassium

37. Elements in sea water Average chemical composition of sea water HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK composition of sea water Salts Grams per litre sodium chloride 24 magnesium chloride 5 sodium sulphate 4 calcium chloride 1.1 potassium chloride 0.7 sodium bicarbonate 0.2 others 0.5 TOTAL 35.5 Potassium Chlorine Sodium characteristics of water

38. Water water molecules (H 2 O) hydrogen bridges 68 % water GO BACK HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK characteristics of water

39. Interactive activity: Atoms and elements HOME HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK

40. Links HOME HOME RESOURCES ACTIVITY LINKS CONTENTS CLOSE BACK GO TO WEBSITE The Periodic Table of Elements GO TO WEBSITE Atoms and the Periodic Table: What is an element?