1. AQA Additional Science
Chemistry 2
Lesson 1.3 Ions

2. Aims Class work 29 June 2007 Ions LO’s What are ions? Write it down!!
Page 43/44
© C Meyer

3. Aims All Know elements react to form compounds
Know the layout of the periodic table
Know what an ion is
Know group 1 reacts with Group 7
Most/Some
Explain how ions form
Work out the charge on an ion

4. What are ions? What are the properties of Sodium?
What are the properties of Chlorine?
Metal, solid, left hand side of
Periodic table, 11 protons,
Electronic structure = 2, 8, 1
Non - metal, gas, right hand side of
Periodic table, 17 protons,
Electronic structure = 2, 8, 7
Demo Na/Cl reaction to make salt m3

5. What are ions? K Al P S Si Mg Na Ar Cl Be N O B C Li Ne F
reactive
gases
metals
Any element from left hand side of table reacts with element from right
1 use of periodic table – predict reactions

6. Elements
Elements are the simplest substances. There are about 100 different elements N S O C Fe K
Each elements has just one particular type of atom that is different to the atoms in any other element N
Even in elements atoms usually join (bond) together.
In some elements atoms bond to form small simple structures.
In other elements atoms bond into giant structures with millions of atoms.

7. Water – a simple structure DNA – a large & complex structure
Compounds
Compounds are formed when different elements chemically react together.
In these reactions different types of atom become chemically bonded.
Like elements some compounds have small simple structures with just a few atoms bonded together
Others compounds have large, complex structures containing thousands or even millions of bonded atoms. O H
Water – a simple structure
DNA – a large & complex structure

8. Compounds are not just mixtures
Reacting is different to just mixing.
The physical and chemical properties of compounds are very different to their original elements.
COMPOUND
ELEMENTS
Sodium Chlorine
Sodium Chloride Na Cl Na Cl
(silver solid)
(green, poison
gas)
(Salt, flavours chips)
Mixture – sand and salt, easy to separate (filter)

9. Rust consists of iron combined with oxygen
Activity
Copy the Table and fill in the last column.
Name
Formula
Element or compound
Rust consists of iron combined with oxygen
Sodium chloride
NaCl
compound
Nickel Ni
element
Copper sulphate
CuSO4
compound
Water
H2O
compound
Oxygen O2
element
Rust
Fe2O3
compound
Mercury Hg
element
Sand
SiO2
compound

10. 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 Be N O B C Li Ne F Al P S Si Mg Na Ar Cl 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.

11. The periodic table the periodic table
Arranging all the elements by atomic number and properties led to the creation of…
the periodic table H He Li Be B C N O Ne F Na Mg Al Si P S Ar Cl K Ca Ga Ge As Se Kr Sc Ti V Cr Mn Fe Co Ni Cu Zn Br Rb Sr In Sn Sb Te Xe Y Zr Nb Mo Tc Ru Pd Ag Cd Rh I Cs Ba Tl Pb Bi Po Rn Hf Ta W Re Os Ir Au Hg La Pt At Fr Ra Rf Db Sg Bh Hs Mt ? Ac

12. Columns of elements Groups What are columns of elements called? 1 2
Group number 3 4 5 6 7 H He Li Be B C N O F Ne
transition elements 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 ? ? ?

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

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

15. 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. H 1 3 11 19 37 55 87 4 21 22 12 23 24 25 26 27 28 29 30 31 32 34 35 20 36 39 40 41 42 43 44 46 47 48 49 50 51 38 52 45 56 72 73 74 75 76 77 79 80 81 82 83 84 57 85 78 88
104
105
106
107
108
109
111
112 89
110 13 15 7 8 16 17 9 10 18 86 53 14 54 2 5 6 33 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 ? ? ?

16. Periodic table H Li Na K Rb Cs Fr Be Sc Ti Mg V Cr Mn Fe Co Ni Cu ZnGa Ge Se Br Ca Kr Y Zr Nb Mo Tc Ru Pd Ag Cd In Sn Sb Sr Te Rh Ba Hf Ta W Re Os Ir Au Hg Tl Pb Bi Po La At Pt Ra Rf Db Sg Bh Hs Mt ? Ac Al P N O S Cl F Ne Ar Rn I Si Xe He B C As
Stick in book and label groups, periods

17. Ions and Electron Structures
Title - Ions
Ions are atoms that have either extra electrons added or electrons removed.
Atoms
Protons
Electrons
Gain 1 electron
Lose 1 electron
1+ ion
Protons
Electrons
So in ions the number of electrons no longer equals the number
of protons
1- ion
Protons
Electrons

18. Positive Ions
These are ions formed by the atom losing one or more electrons.
They are called cations. This is because during electrolysis they move towards the cathode. (Or because they are “pussytive”!).
The charge on the ions is equal to the number of electrons that the atom has lost.
In equations the charge is usually shown above and to the right of the symbol. (E.g. Mg2+ ).
Lost 1 e- +
It is nearly always metal atoms that lose electrons
Ions usually have
OUTER
electron shells that are either completely full or else empty
Lost 2 e- 2+
Lost 3 e- 3+

19. The Electrons in a Sodium Ion
In the sodium atom
Atomic number = number of protons = 11
Number of electrons = 11 23 Na 11
Na+ Na
Bye!
Electron lost
Electron arrangement: (Incomplete Shell)
Electron arrangement: 2.8 (Full Shells)

20. The Electrons in a Magnesium Ion
In the magnesium atom
Atomic number = number of protons = 12
Number of electrons = 12 24 Mg 12
Mg2+ Mg
Bye!
2 electrons lost
Electron arrangement = (Incomplete shell)
Electron arrangement 2.8 (Full Shells)

21. The Lithium Ion 3 How many electrons?
Activity
The Lithium Ion 3
How many electrons?
How many electrons in the first shell?
How many electrons in the second shell?
What electron arrangement?
How many electrons to lose?
New electron arrangement? Include a diagram 7 Li 3 2 1
2.1
1st Shell = 2: full
2nd Shell = 1: not full Li
Li+ 1
Bye!
2.(0)

22. The Boron Ion 5 How many electrons?
Activity
The Boron Ion 5
How many electrons?
How many electrons in the first shell?
How many electrons in the second shell?
What electron arrangement?
How many electrons to lose?
New electron arrangement? 11 B 5 2 3
2.3
1st Shell = 2: full
2nd Shell = 3: not full
Bye! B
B3+ 3
2.(0)

23. What have I learnt?
Write/draw a summary of what you now know about positive ions
Lose or gain electrons?
Go to + or – in electrolysis?
The charge of an ion is less, equal or more than the number of electrons lost?
How are they written?
Draw structure of
Mg ion
(Mg = 12 electrons)
Lose electron
-, Cations, “pussytive”
Equal
Mg2+
Na+, Mg2+ m5

24. Negative Ions.
These are ions formed by the atom gaining one or more electrons.
They are called anions. This is because during electrolysis they move towards the anode.
The charge on the ions is equal to the number of electrons that the atom has gained.
In equations the charge is usually shown above and to the right of the symbol. (E.g.. O2- ).
Gain 1 e- -
It is nearly always non-metal atoms that gain electrons
Ions usually have
OUTER electron shells that are either completely full or else empty
Gain 2 e- 2-
Gain 3 e- 3-

25. The Electrons in a Sulphide Ion.
In the sulphur atom
Atomic number = number of protons = 16
Number of electrons = 16 32 S 16
S2- S
2 electrons gained
Electron arrangement: (incomplete shell)
Electron arrangement (Full shells)

26. The Electrons in a Fluoride Ion.
In the fluorine atom
Atomic number = number of protons = 9
Number of electrons = 9 19 F 9 F- F
1 electron gained
Electron arrangement: (incomplete shell)
Electron arrangement (Full shells)

27. The Oxide Ion 8 How many electrons?
Activity
The Oxide Ion 8
How many electrons?
How many electrons in the first shell?
How many electrons in the second shell?
What electron arrangement?
How many electrons to gain?
New electron arrangement? 16 O 8 2 6
2.6
1st Shell = 2: full
2nd Shell = 6: not full O
O2- 2
2.8

28. What have I learnt?
Write/draw a summary of what you now know about negative ions
Lose or gain electrons?
Go to + or – in electrolysis?
The charge of an ion is less, equal or more than the number of electrons lost?
How are they written?
Draw structure of
O ion
(O 8 electrons)
Gain electron
+, anions
Equal
Cl-, O2-
O2- x m5

29. What have I learnt? Sodium with Chlorine
Write a word equation for the reaction
Write a balanced symbol equation
Label equation with group for elements
Label equation with properties
Draw the sodium and chloride ion structure

30. The End