The document discusses the history and development of the periodic table. It describes early periodic tables from the 1800s with fewer than 40 known elements arranged based on atomic mass. John Newlands proposed the law of octaves but it only worked for the first few elements. Dmitri Mendeleev arranged elements in a periodic way with gaps for undiscovered elements and was able to predict properties. The modern periodic table arranges elements by atomic number and groups them based on electron configuration in the outer shell leading to similar properties within groups. It also discusses trends in reactivity down groups and across periods.

1. CHEMISTRY 3

2. PERIODIC TABLE

3. EARLY PERIODIC
TABLE
• Early 1800s - LESSTHAN 40
ELEMENTS
• NEW ELEMENTS discovered
REGULARLY
• Noticed patterns in the way they worked -
PROPERTIES
• Worked out Atomic Weight

4. JOHN NEWLAND
• In order of ATOMIC MASS
• LAW OF OCTAVES - Similarities in
PROPERTIES of every 8TH ELEMENT

5. JOHN NEWLAND -
Problems
• Some groups had a MIX of METAL and
NON METAL
• Only worked for FIRST FEW
ELEMENTS
• Elements still being discovered

6. DMITRI MENDELEEV
• Arranged in PERIODIC way
• LEFT GAPS for UNDISCOVERED
ELEMENTS
• otherwise elements wouldn’t have
SIMILAR PROPERTIES
• predicted Atomic Mass and Properties
to undiscovered elements.

7. AFTER MENDELEEV...
• ... These were discovered:
• Noble Gases
• Electrons
• Atomic Structure
• accuracies in atomic number ordering
• Groups and Periods (modern table)

8. MODERN PERIODIC
TABLE

9. MODERN PERIODIC
TABLE
• Order by ATOMIC NUMBER - Makes all
elements fit into groups with SIMILAR
PROPERTIES
• GROUPS tell us the number of electrons
in the OUTER SHELL

10. GROUP 1 - ALKALI
METALS
• All LOW DENSITY
• React w/ NON-METALS = IONIC
COMPOUNDS
• React w/ WATER = RELEASE
HYDROGEN
• Form HYDROXIDES that dissolve in
water = ALKALINE SOLUTION

11. GROUP 1 - ALKALI
METALS
• The FURTHER DOWNTHE GROUP
the MORE REACTIVETHE ELEMENT
• The LOWER the MELTING&BOILING
POINT
• Purple flame - SODIUM AND
ONWARDS

12. GROUP 2
TRANSITION METALS
• COMPARED TO GROUP 1 - HIGHER
MELTING&BOILING POINTS except
for mercury.
• HARDER&STRONGER
• LESS reactive, don’t react as much with
WATER&OXYGEN

13. GROUP 2
TRANSITION METALS
• Build buildings due to being LESS
REACTIVE
• Form IONS with different charges
• Form COLOURED compounds
[COPPER SULFATE - BLUE]
• Useful as CATALYSTS

14. GROUP 7
HALOGENS
• Bad conductors
• POISONOUS
• Coloured vapours
• React with METALS to form IONIC
COMPOUNDS [ SODIUM CHLORIDE]

15. GROUP 7
HALOGENS
• ION produced called HALIDE
• E.G. Fluorine - Fluoride etc.
• Each has -1 Charge
• FURTHER DOWN - LESS reactive
• HIGHER Melting & Boiling points

16. GROUP 7
HALOGENS
• DIATONIC MOLECULES
• Higher the reactivity , in
DISPLACEMENT reaction, element with
HIGHER reactivity will displace lower
reacivity.

17. TRENDS IN
REACTIVITY

18. TRENDS IN
REACTIVITY
• GROUP 1 DOWN - MORE reactive
• GROUP 7 DOWN - LESS reactive
• The HIGHER the energy level of the
OUTER ELECTRONS:
• The easier electrons are LOST
• The LESS easily electrons are GAINED

19. TRENDS IN
REACTIVITY
• GROUP 1 elements need to LOSE
electrons to react.
• LESS ENERGY LEVELS:
• STRONGER attraction [ To NUCLEUS]
• Less SCREENING/SHIELDING by
INNER ELECTRONS
• Electrons lost LESS easily

20. TRENDS IN
REACTIVITY
• MORE ENERGY LEVELS:
• Outer Electron FURTHER from nucleus
• WEAKER attraction [ TO NUCLEUS]
• MORE screening/Shielding by inner
electrons
• Electron lost EASILY

21. GROUP 7
REACTIVITY
• Needs to GAIN electron
• LESS energy levels :
• Outer electron CLOSER to nucleus
• Stronger attraction [ TO NUCLEUS]
• LESS screening/shielding by INNER
ELECTRONS

22. GROUP 7
REACTIVITY
• MORE energy levels :
• Outer electron FURTHER to nucleus
• Weaker attraction [ TO NUCLEUS]
• MORE screening/shielding by INNER
ELECTRONS

23. HARD AND SOFT
WATER

24. INTRO
• SOFT water : can LATHER [produce
bubbles when soaped]
• HARD water : CAN’T Lather : creates
SCUM&SCALE
• contains DISSOLVED COMPOUNDS
• AND MAGNESIUM&CALCIUM
compounds [river flows over substances]

25. HARD WATER
• SCUM : INSOLUBLE precipitate
• Formed by REACTION with SOAP
• CA2+ [Calcium Ion] REACTS with
HARD WATER
• MORE soap needed [more expensive]
• SOAPLESS detergents made to avoid
scum [no Sodium Stearate won’t react]

26. HARD WATER
• SCALE : INSOLUBLE SOLID
• REDUCES efficiency
• E.G. Kettle - SCALE is POOR
CONDUCTOR OF HEAT - Kettle has
to work harder to heat water.
• BENEFITS : Bone development ;Teeth
development ; Reduce Heart Disease

27. HARD WATER
• TEMPORARY - Softened by
Heating/Boiling
• PERMANENT - Remains hard even when
Heated / Boiled

28. SOFTENING HARD
WATER
• Contains CA2+ [CALCIUM IONS]
• Contains MG2+ [MAGNESIUM IONS]
• TO SOFTEN - Add WASHING SODA
(Sodium Carbonate) =

29. SOFTENING USING
WASHING SODA• 1.TO SOFTEN - Add WASHING
SODA (Sodium Carbonate) =
• Calcium Ions + Carbonate ions = Calcium
Carbonate + Sodium

30. SOFTENING USING
ION EXCHANGE
• 2. Use ION EXCHANGE COLUMN
• Cylinder containing RESIN containing
SODIUM (NA+) or HYDROGEN
(MG2+) ions
• Magnesium&Calcium ions exchange
with Sodium/Hydrogen ions
• Sodium/Hydrogen Ions left in water

31. TEMPORARY HARD
WATER
• Softened when HEATED
• contains HCO -₃⁻ Hydrogen Carbonate
Ions
• HCO₃⁻ DECOMPOSES to
CARBONATE IONS
• Carbonate Ions REACT with magnesium
ions / Calcium Ions to form carbonates

32. TITRATION

33. TITRATION METHOD
• The METHOD to see how much ACID
or ALKALI is needed to create a
NEUTRAL SOLUTION.
• 1. measure and add volume of ALKALI
into CONICAL FLASK using a
PIPETTE
• 2. measure drops of Phenolphthalein/
Methyl Orange

34. TITRATION METHOD
• 3. Pour acid in BURETTE and RECORD
READING
• 4. OPEN TAP in Burette, add little acid,
swirl conical flask to mix.
• 5.ADD ACID until solution is
NEUTRAL (shown by indicator)& repeat
• Pheno - Pink to Colourless

35. TITRATION
CALCULATION
• Should be able to calculate QUANTITIES
in titrations involving :
• concentrations - MOLES per dm³
• masses - GRAMS per dm³
• If conc. of one reactant is known, it
can be used to find the conc. of the
other reactant.

36. TITRATION
CALCULATION
• 1 decimetre cubed = 1000cm³ = 1 LITRE
• CONC. OF SOLUTION = Moles per
dm³ [ 3 moles per 1 dm³ ]
• MOLES - mass [g] of 1 MOLE of a
substance is it’s RELATIVE FORMULA
MASS in Grams. [ Add all relative atomic
masses in a compound together = 1 mole]

37. TITRATION
CALCULATION E.G.
• Make 1 mole per dm³ solution of Sodium
Hydroxide NaOH
• Relative atomic masses =
• Na=23 O=16 H=1 1 MOLE = 40g
• Take 1dm³ [1000 cm³ ] of water and put
40g of NaOH in it

38. TITRATION
CALCULATION E.G.2
• Put 40g in 500cm³ of water , what is the
Concentration in Moles/dm³?
• 500cm³ is half 1dm³ , so you Double the
mass = 80g = 2 moles/dm³

39. TITRATION
CALCULATION E.G.3
• What MASS of sodium hydroxide is there
in 250 cm³ of a 2 moles/dm³ solution?
• 2 mol = 80g
• 250cm³ = 1/4 of 1000
• 1/4 x 80g = 20g

40. TITRATION
CALCULATION E.G.4
• We have 45cm³ of Sodium Hydroxide
solution, and 0.2 mol/dm³ which has
neutralised 15cm³ of Ethanoic acid.
• What is :The conc. of Ethanoic Acid in
• a) mol/dm³
• b) grams/dm³ = M Ethanoic Acid = 60ᵣ

41. TITRATION
CALCULATION E.G.4
• a)

42. TITRATION
CALCULATION E.G.4

43. TITRATION
PRACTICE QUEST
• 25.0 cm³ of ACID is placed into a conical
flask.The concentration of acid = ?
• The ACID was Neutralised (reacted
completely) with 13.5cm³ of sodium
Hydroxide of conc. 0.10 mol/dm³
• Calculate the Conc. in mol/dm³
• 1 mole Sodium Hydroxide = 1 mole acid

44. TITRATION
PRACTICE QUEST

45. TITRATION
PRACTICE 2
• Titration is done to find concentration of
SULPHURIC ACID. 25.0cm³ of the
sulphuric acid solution was
NEUTRALISED by 34.0cm³ of a
POTASSIUM HYDROXIDE solution of
2.0 mol/dm³
• Equation for reaction is =

46. TITRATION
PRACTICE 2

47. ENERGY LEVEL
DIAGRAMS

48. ENERGY LEVEL
DIAGRAM
• The reaction is either ENDOTHERMIC
or EXOTHERMIC
• Energy needs to be supplied to the atoms
to BREAKTHE BONDS and this takes
energy from the environment.
• When making bonds, energy is
RELEASED to the environment.

49. ENERGY LEVEL
DIAGRAM• If the graph shows a higher energy going
to a lower energy level, it is
EXOTHERMIC, as energy is released.