Presentation on theme: "Atomic structure. Atomic Structure The structure of the atom ELECTRON – negative, mass nearly nothing PROTON – positive, same mass as neutron (“1”) NEUTRON."— Presentation transcript:
The structure of the atom ELECTRON – negative, mass nearly nothing PROTON – positive, same mass as neutron (“1”) NEUTRON – neutral, same mass as proton (“1”) The Ancient Greeks used to believe that everything was made up of very small particles. I did some experiments in 1808 that proved this and called these particles ATOMS: Dalton
The Atom Nucleus Electron Shell or Orbit
The Atom Hydrogen Proton Electron Hydrogen has one proton, one electron and NO neutrons
The Atom Helium Electron Proton Neutron Helium has two electrons, two protons and two neutrons
Mass and atomic number ParticleRelative MassRelative Charge Proton11 Neutron10 Electron0 MASS NUMBER = number of protons + number of neutrons SYMBOL PROTON NUMBER = number of protons (obviously)
The Atom Helium Electron Proton Neutron Helium has two electrons, two protons and two neutrons
The Atom Lithium Protons Neutrons Electrons
The Atom Beryllium Protons Neutrons Electrons Beryllium has four electrons, four protons and five neutrons.
The Atom Boron Protons Neutrons Electrons Boron has five electrons, five protons and six neutrons.
The Atom Carbon Protons Neutrons Electrons Carbon has six electrons, six protons and six neutrons.
The Atom Nitrogen Protons Neutrons Electrons Nitrogen has seven electrons, seven protons and seven neutrons.
The Atom Oxygen Protons Neutrons Electrons Oxygen has eight electrons, eight protons and eight neutrons.
The Atom Fluorine Protons Neutrons Electrons Fluorine has nine electrons, nine protons and ten neutrons.
The Atom Neon Protons Neutrons Electrons Neon has ten electrons, ten protons and ten neutrons.
The Atom Sodium Protons Neutrons Electrons Sodium has eleven electrons, eleven protons and twelve neutrons.
How many protons, neutrons and electrons?
Mendeleev Periodic table The periodic table arranges all the elements in groups according to their properties. Horizontal rows are called PERIODS Vertical columns are called GROUPS
HHe LiBeBCNOFNe Na MgMg AlSiPSClAr KCaFeNi CuCu ZnBrKr AgIXe Pt AuAu HgHg The Periodic Table Fact 1: Elements in the same group have the same number of electrons in the outer shell (this correspond to their group number) E.g. all group 1 metals have __ electron in their outer shell These elements have __ electrons in their outer shell These elements have __ electrons in their outer shells
HHe LiBeBCNOFNe Na MgMg AlSiPSClAr KCaFeNi CuCu ZnBrKr AgIXe Pt AuAu HgHg The Periodic Table Fact 2: As you move down through the periods an extra electron shell is added: E.g. Lithium has 3 electron in the configuration 2,1 Potassium has 19 electrons in the configuration __,__,__ Sodium has 11 electrons in the configuration 2,8,1
HHe LiBeBCNOFNe Na MgMg AlSiPSClAr KCaFeNi CuCu ZnBrKr AgIXe Pt AuAu HgHg The Periodic Table Fact 3: Most of the elements are metals: These elements are metals This line divides metals from non- metals These elements are non-metals
HHe LiBeBCNOFNe Na MgMg AlSiPSClAr KCaFeNi CuCu ZnBrKr AgIXe Pt AuAu HgHg The Periodic Table Fact 4: (Most important) All of the elements in the same group have similar PROPERTIES. This is how I thought of the periodic table in the first place. This is called PERIODICITY. E.g. consider the group 1 metals. They all: 1)Are soft 2)Can be easily cut with a knife 3)React with water
Group 1 – The alkali metals Li Na K Rb Cs Fr
Group 1 – The alkali metals 1) These metals all have ___ electron in their outer shell Some facts… 2) Reactivity increases as you go _______ the group. This is because the electrons are further away from the _______ every time a _____ is added, so they are given up more easily. 3) They all react with water to form an alkali (hence their name) and __________, e.g: Words – down, one, shell, hydrogen, nucleus Potassium + water potassium hydroxide + hydrogen 2K (s) + 2H 2 O (l) 2KOH (aq) + H 2(g)
Group 0 – The Noble gases He Ne Ar Kr Xe Rn
Group 0 – The Noble gases Some facts… 1) All of the noble gases have a full outer shell, so they are very _____________ 2) They all have low melting and boiling points 3) They exist as single atoms rather then diatomic molecules 4)Helium is lighter then air and is used in balloons and airships (as well as for talking in a silly voice) 5)Argon is used in light bulbs (because it is so unreactive) and argon, krypton and neon are used in fancy lights
Group 7 – The halogens F Cl Br I At
Group 7 – The Halogens Some facts… 1) Reactivity DECREASES as you go down the group Decreasing reactivity (This is because the electrons are further away from the nucleus and so any extra electrons aren’t attracted as much). 2) They exist as diatomic molecules (so that they both have a full outer shell): Cl 3) Because of this fluorine and chlorine are liquid at room temperature and bromine is a gas
The halogens – some reactions 1) Halogen + metal: Na + Cl - Na Cl + 2) Halogen + non-metal: H Cl + H Halogen + metal ionic salt Halogen + non-metal covalent molecule
How shells fill The first electron shell can only hold a maximum of two electrons. The second electron shell can hold a maximum of eight electrons. The third electron shell can also hold a maximum of eight electrons. The fourth electron shell can also hold eight electrons.
Electron structure Consider an atom of Potassium: Potassium has 19 electrons. These are arranged in shells… Nucleus The inner shell has __ electrons The next shell has __ electrons The next shell has the remaining __ electron Electron structure = 2,8,8,1
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Hydrogen H 1 electron0 electron Helium He 2 electron0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Lithium Li 2 electron1 electron0 electron Beryllium Be 2 electron 0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Boron B 2 electron3 electron0 electron Carbon C 2 electron4 electron0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Nitrogen N 2 electron5 electron0 electron Oxygen O 2 electron6 electron0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Fluorine F 2 electron7 electron0 electron Neon Ne 2 electron8 electron0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Sodium Na 2 electron8 electron1 electron0 electron Magnesium Mg 2 electron8 electron2 electron0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Aluminium Al 2 electron8 electron3 electron0 electron Silicon Si 2 electron8 electron4 electron0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Phosphorus P 2 electron8 electron5 electron0 electron Sulphur S 2 electron8 electron6 electron0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Chlorine Cl 2 electron8 electron7 electron0 electron Argon Ar 2 electron8 electron 0 electron
How the shells fill with electrons ElementShell 1Shell 2Shell 3Shell 4 Potassium2 electron8 electron 1 electron Calcium Ca 2 electron8 electron 2 electron
The First Twenty Elements Hydrogen 1,0,0,0 Helium 2,0,0,0 Lithium 2,1,0,0 Beryllium 2,2,0,0 Boron 2,3,0,0 Carbon 2,4,0,0 Nitrogen 2,5,0,0
First 20 Elements continued Oxygen 2,6,0,0 Fluorine 2,7,0,0 Neon 2,8,0,0 Sodium 2,8,1,0 Magnesium 2,8,2,0 Aluminium 2,8,3,0 Silicon 2,8,4,0
First 20 Elements continued Phosphorus 2,8,5,0 Sulphur 2,8,6,0 Chlorine 2,8,7,0 Argon 2,8,8,0 Potassium 2,8,8,1 Calcium 2,8,8,2
The Alkali metals Lithium, Sodium and Potassium have one electron in their outer shell and this is why they are found in group one of the periodic table.
The Nobel gases The Nobel gases have full outer shells and they are found in group 0 of the periodic table. Helium, Neon, Argon, Krypton, Xenon and Radon.
The Halogens Fluorine, Chlorine, Bromine and Iodine are the Halogens and they all have seven electrons in their outer shell. This is why they are found in group 7 of the periodic table.
Displacement Fluorine can displace Chlorine, Bromine and Iodine. F Cl Br I
Displacement Chlorine can displace Bromine and Iodine but it cannot displace Fluorine Cl Br I F
Displacement Bromine can displace Iodine but it cannot displace Fluorine or Chlorine Br I F Cl
Displacement Iodine cannot displace Iodine Fluorine, Chlorine or Bromine I F Cl Br
Fluorine reacts with sodium chloride. Which equation is correctly shows this reaction? F 2 + 2Na 2NaF F + Na NaF 2F + 2Na 2NaF
Which will displace? 2NaF + Cl 2 Yes or No 2NaBr + Cl 2 Yes or No 2KI + I 2 Yes or No 2LiCl + I 2 Yes or No 2NaBr + I 2 Yes or No 2NaBr + F 2 Yes or No Cl 2 + 2NaBr Yes or No
Four factors affecting Reaction Rate Catalysts Temperature Concentration Surface Area
Catalyst A catalyst speeds up or slows down a reaction but does not get used up by the reaction.
Temperature If we increase the temperature of a reaction by 10 0 C the rate will double this means the reaction will be complete in half the time.
Concentration If we increase the concentration of a reactant the number of particles increase that in turn increases the chance of a collision and initiates a chemical reaction.
Surface area The larger the particle size the smaller the relative area the slower the reaction. The smaller the particle size the greater the relative surface area and the faster the reaction.
Group 1 Lithium, sodium and potassium are all in group 1. They all have one electron in the outer shell. They are all metals. They react with group 7 to form metal halides.
Group 7 Fluorine,Chlorine, Bromine and Iodine. They all have 7 electrons in their outer shell. They are all coloured. They form metal halides with group 1 metals.
Group 0 These are the noble gases. They have complete electron shells. The electron shells are full. They are unreactive. They are inert. They do not react. They include, Helium, Neon, Argon, Krypton, Xenon and Radon
Halogens Name Fluorine Colour Pale Yellow State Gas M.P B.P ChlorineGreenGas BromineBrownLiquid-759 IodineSlate grey Solid114184
Reactions Sodium and Chlorine react to form Sodium Chloride. Iron and Chlorine react to form Iron Chloride. 2Na + Cl 2 2NaCl. Fe + Cl 2 FeCl 2.
Uses of the Halogens Fluorine is put into water supplies to kill harmful bacteria and to help keep teeth healthy. Chlorine is used in swimming pools to bacteria in the water. Bromine is used in pesticides. Silver bromide is used in photography. Iodine is an antiseptic on cuts and grazes.