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3. 1 1 KS3 SCIENCE - CHEMISTRY KS3 SCIENCE - CHEMISTRY Atoms & Elements Atoms & Elements

4. 2 2 THE NATURE OF ATOMS

5. 3 3 Atoms have a Nucleus, which contains Neutrons (no Charge) and Protons (+ve Charge), Atoms have a Nucleus, which contains Neutrons (no Charge) and Protons (+ve Charge), The Nucleus of a Beryllium atom has four protons The Nucleus of a Beryllium atom has four protons ++ ++ ++ ++

6. 4 4 THE NATURE OF ATOMS Atoms of Beryllium also have four even tinier Electrons (-ve Charge) which fly around the nucleus Atoms of Beryllium also have four even tinier Electrons (-ve Charge) which fly around the nucleus

7. 5 5 THE NATURE OF ATOMS Electrons move in a series of layers or Shells, and take up most of the space in an atom Electrons move in a series of layers or Shells, and take up most of the space in an atom

8. 6 6 THE NATURE OF ATOMS Different Elements have different numbers of neutrons, protons and electrons in their atoms Different Elements have different numbers of neutrons, protons and electrons in their atoms All the atoms in an element have the same number of protons in the nucleus All the atoms in an element have the same number of protons in the nucleus

9. 7 7 PROPERTIES OF ELEMENTS

10. 8 8 Elements are the building blocks of all substances, and they cannot be split into anything simpler than an atom by chemical means Elements are the building blocks of all substances, and they cannot be split into anything simpler than an atom by chemical means OOOO In some elements atoms form into groups called Molecules, e.g. Oxygen is O 2 In some elements atoms form into groups called Molecules, e.g. Oxygen is O2O2

11. 9 9 PROPERTIES OF ELEMENTS There are about 100 elements, and we can list them in the Periodic Table, so that elements with similar properties are in the same column There are about 100 elements, and we can list them in the Periodic Table, so that elements with similar properties are in the same column Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H

12. 10 PROPERTIES OF ELEMENTS Noble Gases Noble Gases Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H Non Metals Non Metals Metals & Metalloids Metals & Metalloids Transition Metals Transition Metals Reactive Metals Reactive Metals

13. 11 PROPERTIES OF ELEMENTS Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H Alkali Metals Alkali Metals These metals are very reactive, and become more reactive as you go down the group These metals are very reactive, and become more reactive as you go down the group

14. 12 PROPERTIES OF ELEMENTS Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H Alkaline Earths Alkaline Earths These metals are reactive, though not as much as the first group These metals are reactive, though not as much as the first group

15. 13 PROPERTIES OF ELEMENTS Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H Transition Metals Transition Metals These are usually hard, Dense metals, less reactive than those in the first two groups These are usually hard, Dense metals, less reactive than those in the first two groups

16. 14 PROPERTIES OF ELEMENTS Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H Silicon & Germanium Silicon & Germanium Semiconductors border metals and non-metals Semiconductors border metals and non-metals

17. 15 PROPERTIES OF ELEMENTS Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H Halogens Useful for hygiene - Iodine for wounds and Chlorine to disinfect swimming pools Useful for hygiene - Iodine for wounds and Chlorine to disinfect swimming pools

18. 16 PROPERTIES OF ELEMENTS Li Na K K Rb Cs Be Mg Ca Ba Sc Y Y La Ti Zr Hf V V Nb Ta Cr Mo W W Mn Tc Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg B B Al Ga In Tl C C Si Ge Sn Pb N N P P As Sb Bi O O S S Se Te Po F F Cl Br I I At He Ne Ar Kr Xe Rn H H These exist as single atoms These exist as single atoms Noble Gases Noble Gases

19. 17 COMBINING ELEMENTS

20. 18 COMBINING ELEMENTS When two or more elements join together chemically, substances formed are called Compounds When two or more elements join together chemically, substances formed are called Compounds The smallest particle in a compound is a Molecule, formed from the atoms of at least two elements The smallest particle in a compound is a Molecule, formed from the atoms of at least two elements

21. 19 COMBINING ELEMENTS When two elements combine to form a compound, this is a Chemical Reaction When two elements combine to form a compound, this is a Chemical Reaction