1. A CLOSER LOOK AT
ELECTRON CONFIGURATION

2. THE RULES
• Theaufbau principle states that the elctrons occupy the
lowest available energy level providing the atom is in the
ground state.
• Hunds Rule of multiplicity: Electrons occupy sublevels singlely
before occuplying them pairs
• Pauli
Exclusion principle states that no more than 2 e- can
occupy an orbital and then only do so if they have an opposite
spin

3. GROUND STATE AND
GROUND STATE
• Ground state: All electrons in the lowest level
• Excited state: An electron in a higher state than the ground
state
• The relationship between the ground state and excited state is
E2 - E1 = hf

5. NOTES
• An electron is promoted to an excited state with heat
• Electrons
cannot occupy spaces between shells because it
would be unstable
• Anelectron will not stay in the excited state because it is
unstable
• When the electron goes from the ground state to the excited
state it emits light at a frequency, f.

6. QUANTUM NUMBERS
• Each electron in an atom has four quantum numbers
• Principal quantum number, n: main energy level
• Subsidiary quantum number, l: gives energy sub-level
• Magnetic quantum number, m: gives orbital direction
• Spin quantum number, s: gives the spin of the electron

7. Principal quantum number, n: main energy level
• The principal quantum number (n) describes the size of the
orbital. Orbitals for which n = 2 are larger than those for which n
= 1, for example.

8. Subsidiary quantum number, l: gives energy sub-
level
• The subsidiary quantum number (l) describes the shape of the orbital.
• s=0
• p=1
• d=2
• f=3
•

9. Magnetic quantum number, m: gives orbital
direction
• magnetic quantum number (m), to describe the orientation in
space of a particular orbital.

10. FIND THE FOUR QUANTUM NUMBERS
OF THE LAST ELECTRON IN THE
FOLLOWING
• Li
• Cl
•B
•O
• Ar

11. 2006 QUESTION 8

12. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+

13. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+

14. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+

15. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond

16. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons

17. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond

18. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond
unequal sharing (distribution) of electrons (charge) // small EN difference / EN
difference < 1.7

19. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond
unequal sharing (distribution) of electrons (charge) // small EN difference / EN
difference < 1.7
(iii) electronegativity.

20. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond
unequal sharing (distribution) of electrons (charge) // small EN difference / EN
difference < 1.7
(iii) electronegativity.
attraction an atom (element) has has for a shared pair of electrons

21. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond
unequal sharing (distribution) of electrons (charge) // small EN difference / EN
difference < 1.7
(iii) electronegativity.
attraction an atom (element) has has for a shared pair of electrons
Use electronegativity values to predict the type of bonding in potassium
bromide.

22. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond
unequal sharing (distribution) of electrons (charge) // small EN difference / EN
difference < 1.7
(iii) electronegativity.
attraction an atom (element) has has for a shared pair of electrons
Use electronegativity values to predict the type of bonding in potassium
bromide.
ionic bonding [KBr / two correct EN values / EN difference = 2.0 ...3]

23. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond
unequal sharing (distribution) of electrons (charge) // small EN difference / EN
difference < 1.7
(iii) electronegativity.
attraction an atom (element) has has for a shared pair of electrons
Use electronegativity values to predict the type of bonding in potassium
bromide.
ionic bonding [KBr / two correct EN values / EN difference = 2.0 ...3]
What are the general properties of compounds with this type of bonding?

24. 2006 QUESTION 8
• (a) Write the electron configuration of (i) the carbon atom (ii) the aluminium
ion, Al 3+
(i) C = 1s2 2s2 2p2 (ii) Al 3+ = [1s2 2s2 2p6]3+
(b) Define (i) a covalent bond
sharing of electrons
(ii) a polar covalent bond
unequal sharing (distribution) of electrons (charge) // small EN difference / EN
difference < 1.7
(iii) electronegativity.
attraction an atom (element) has has for a shared pair of electrons
Use electronegativity values to predict the type of bonding in potassium
bromide.
ionic bonding [KBr / two correct EN values / EN difference = 2.0 ...3]
What are the general properties of compounds with this type of bonding?
high melting points, high boiling points, soluble in water, conduct electricity when
molten or in aqueous solution, fast reactions, solid etc

26. • (c) What type of crystal exists in each of these substances?

27. • (c) What type of crystal exists in each of these substances?
iodine: molecular crystal
aluminium: metallic (metal) crystal
diamond: covalent /atomic crystal

28. • (c) What type of crystal exists in each of these substances?
iodine: molecular crystal
aluminium: metallic (metal) crystal
diamond: covalent /atomic crystal
Explain, in terms of bonding, why (i) iodine is insoluble in water

29. • (c) What type of crystal exists in each of these substances?
iodine: molecular crystal
aluminium: metallic (metal) crystal
diamond: covalent /atomic crystal
Explain, in terms of bonding, why (i) iodine is insoluble in water
iodine is non-polar will dissolve in non-polar solvent / water is polar
covalent

30. • (c) What type of crystal exists in each of these substances?
iodine: molecular crystal
aluminium: metallic (metal) crystal
diamond: covalent /atomic crystal
Explain, in terms of bonding, why (i) iodine is insoluble in water
iodine is non-polar will dissolve in non-polar solvent / water is polar
covalent
(ii) aluminium is a good conductor of electricity

31. • (c) What type of crystal exists in each of these substances?
iodine: molecular crystal
aluminium: metallic (metal) crystal
diamond: covalent /atomic crystal
Explain, in terms of bonding, why (i) iodine is insoluble in water
iodine is non-polar will dissolve in non-polar solvent / water is polar
covalent
(ii) aluminium is a good conductor of electricity
free electrons / cloud of valence electrons [to carry current ...3]

32. • (c) What type of crystal exists in each of these substances?
iodine: molecular crystal
aluminium: metallic (metal) crystal
diamond: covalent /atomic crystal
Explain, in terms of bonding, why (i) iodine is insoluble in water
iodine is non-polar will dissolve in non-polar solvent / water is polar
covalent
(ii) aluminium is a good conductor of electricity
free electrons / cloud of valence electrons [to carry current ...3]
(iii) diamond is difficult to cut.

33. • (c) What type of crystal exists in each of these substances?
iodine: molecular crystal
aluminium: metallic (metal) crystal
diamond: covalent /atomic crystal
Explain, in terms of bonding, why (i) iodine is insoluble in water
iodine is non-polar will dissolve in non-polar solvent / water is polar
covalent
(ii) aluminium is a good conductor of electricity
free electrons / cloud of valence electrons [to carry current ...3]
(iii) diamond is difficult to cut.
atoms held by strong bonds / tetrahedral structure [all valencies satisfied ...3]

34. 2005 QUESTION 8

35. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom

36. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2

37. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom

38. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1

39. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+

40. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+

41. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?

42. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3

43. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3
Define first ionisation energy of an element

44. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3
Define first ionisation energy of an element
energy required to remove most loosely bound / first / outermost electron from a
neutral / gaseous atom

45. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3
Define first ionisation energy of an element
energy required to remove most loosely bound / first / outermost electron from a
neutral / gaseous atom
State and account for the general trend in first ionisation energy values from Li to
Ne on the periodic table (ionisation energies) increase decreasing / nuclear charge

46. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3
Define first ionisation energy of an element
energy required to remove most loosely bound / first / outermost electron from a
neutral / gaseous atom
State and account for the general trend in first ionisation energy values from Li to
Ne on the periodic table (ionisation energies) increase decreasing / nuclear charge
Explain why the first ionisation energy of beryllium is larger than that of boron

47. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3
Define first ionisation energy of an element
energy required to remove most loosely bound / first / outermost electron from a
neutral / gaseous atom
State and account for the general trend in first ionisation energy values from Li to
Ne on the periodic table (ionisation energies) increase decreasing / nuclear charge
Explain why the first ionisation energy of beryllium is larger than that of boron
Be has a full sub-shell // B has one electron in sub-shell // Be has a stable electron
configuration

48. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3
Define first ionisation energy of an element
energy required to remove most loosely bound / first / outermost electron from a
neutral / gaseous atom
State and account for the general trend in first ionisation energy values from Li to
Ne on the periodic table (ionisation energies) increase decreasing / nuclear charge
Explain why the first ionisation energy of beryllium is larger than that of boron
Be has a full sub-shell // B has one electron in sub-shell // Be has a stable electron
configuration

49. 2005 QUESTION 8
• (a)Write the electronic (s, p) configuration of (i) the beryllium atom
Be = 1s2 2s2
(ii) the sodium atom
Na=1s2 2s2 2p2 3s1
(iii) the sodium ion, Na+
Na+ = [1s2 2s2 2p6]+
What is the principal quantum number of the outermost electron in a sodium atom?
3
Define first ionisation energy of an element
energy required to remove most loosely bound / first / outermost electron from a
neutral / gaseous atom
State and account for the general trend in first ionisation energy values from Li to
Ne on the periodic table (ionisation energies) increase decreasing / nuclear charge
Explain why the first ionisation energy of beryllium is larger than that of boron
Be has a full sub-shell // B has one electron in sub-shell // Be has a stable electron
configuration

51. • (b) Define an ionic bond

52. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]

53. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.

54. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine

55. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine
electron transfer from sodium to chlorine

56. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine
electron transfer from sodium to chlorine

57. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine
electron transfer from sodium to chlorine
Describe the crystal structure of sodium chloride

58. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine
electron transfer from sodium to chlorine
Describe the crystal structure of sodium chloride
ions occupy the lattice points, ions occupy alternate positions, unit repeats itself, each sodium ion (Na+)
is surrounded by 6 chloride (Cl ̄)ions, each chloride (Cl ̄) ion is surrounded by 6 sodium (Na+) ions,
consists of a three dimensional cubic latticeany three

59. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine
electron transfer from sodium to chlorine
Describe the crystal structure of sodium chloride
ions occupy the lattice points, ions occupy alternate positions, unit repeats itself, each sodium ion (Na+)
is surrounded by 6 chloride (Cl ̄)ions, each chloride (Cl ̄) ion is surrounded by 6 sodium (Na+) ions,
consists of a three dimensional cubic latticeany three

60. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine
electron transfer from sodium to chlorine
Describe the crystal structure of sodium chloride
ions occupy the lattice points, ions occupy alternate positions, unit repeats itself, each sodium ion (Na+)
is surrounded by 6 chloride (Cl ̄)ions, each chloride (Cl ̄) ion is surrounded by 6 sodium (Na+) ions,
consists of a three dimensional cubic latticeany three
Give two general properties of ionic compounds.

61. • (b) Define an ionic bond
• attraction between oppositely charged ions // transfer of electrons between two atoms...6 [E.N.
difference > 1.7 ...3]
Use diagrams to show the formation of a bond between a sodium atom and a chlorine atom.
one electron in valence shell sodium seven electrons in valence shell chlorine
electron transfer from sodium to chlorine
Describe the crystal structure of sodium chloride
ions occupy the lattice points, ions occupy alternate positions, unit repeats itself, each sodium ion (Na+)
is surrounded by 6 chloride (Cl ̄)ions, each chloride (Cl ̄) ion is surrounded by 6 sodium (Na+) ions,
consists of a three dimensional cubic latticeany three
Give two general properties of ionic compounds.
high melting points, high boiling points, soluble in water, conduct electricity when molten or in solution,
hard, solid, crystalline etc any two

62. 2009 QUESTION 8

63. 2009 QUESTION 8
• Explain the term atomic orbital.
2×3 region in space/ around
the nucleus / in an atom
...3 [area unacceptable] where there is a
high probability of finding an electron
...3

64. 2009 QUESTION 8
• Explain the term atomic orbital.
2×3 region in space/ around
the nucleus / in an atom
...3 [area unacceptable] where there is a
high probability of finding an electron
...3
Write the electron configuration of (i)
carbon atom,
6
a

65. 2009 QUESTION 8
• Explain the term atomic orbital.
2×3 region in space/ around
the nucleus / in an atom
...3 [area unacceptable] where there is a
high probability of finding an electron
...3
Write the electron configuration of (i)
carbon atom,
6
a
1s2 2s2 2px 1 2py1 / 1s2 2s2 2p2
...6

66. 2009 QUESTION 8
• Explain the term atomic orbital.
2×3 region in space/ around
the nucleus / in an atom
...3 [area unacceptable] where there is a
high probability of finding an electron
...3
Write the electron configuration of (i)
carbon atom,
6
a
1s2 2s2 2px 1 2py1 / 1s2 2s2 2p2
...6
(ii)
an iron atom.
2×3

67. 2009 QUESTION 8
• Explain the term atomic orbital.
2×3 region in space/ around
the nucleus / in an atom
...3 [area unacceptable] where there is a
high probability of finding an electron
...3
Write the electron configuration of (i)
carbon atom,
6
a
1s2 2s2 2px 1 2py1 / 1s2 2s2 2p2
...6
(ii)
an iron atom.
2×3
1s2 2s2 2p6 3s2 3p6
...3 4s2 3d6
...3

69. • (a)
Diamond and graphite are crystalline solids of carbon. Explain in
terms of bonding why diamond and graphite differ (i)
in their
hardness,
2×3

70. • (a)
Diamond and graphite are crystalline solids of carbon. Explain in
terms of bonding why diamond and graphite differ (i)
in their
hardness,
2×3
• strong / covalent bonds in diamond
...3 weak van der Waals bonds (hold)
graphite (layers together)/each carbon atom forms three strong/covalent bonds
and one weak (van der Waals) bond (to another layer of carbon atoms)...3

71. • (a)
Diamond and graphite are crystalline solids of carbon. Explain in
terms of bonding why diamond and graphite differ (i)
in their
hardness,
2×3
• strong / covalent bonds in diamond
...3 weak van der Waals bonds (hold)
graphite (layers together)/each carbon atom forms three strong/covalent bonds
and one weak (van der Waals) bond (to another layer of carbon atoms)...3
(ii)
in their ability to conduct electricity.
2×3

72. • (a)
Diamond and graphite are crystalline solids of carbon. Explain in
terms of bonding why diamond and graphite differ (i)
in their
hardness,
2×3
• strong / covalent bonds in diamond
...3 weak van der Waals bonds (hold)
graphite (layers together)/each carbon atom forms three strong/covalent bonds
and one weak (van der Waals) bond (to another layer of carbon atoms)...3
(ii)
in their ability to conduct electricity.
2×3
no free electrons in diamond /(valence) electrons in diamond involved in
covalent bonding/localised/not free to move/unavailable

73. • (a)
Diamond and graphite are crystalline solids of carbon. Explain in
terms of bonding why diamond and graphite differ (i)
in their
hardness,
2×3
• strong / covalent bonds in diamond
...3 weak van der Waals bonds (hold)
graphite (layers together)/each carbon atom forms three strong/covalent bonds
and one weak (van der Waals) bond (to another layer of carbon atoms)...3
(ii)
in their ability to conduct electricity.
2×3
no free electrons in diamond /(valence) electrons in diamond involved in
covalent bonding/localised/not free to move/unavailable
(some valence) electrons in graphite involved in delocalised bonding/free to
move/available

75. • (b)
Iron is a transition metal. How is a transition element
identified from its electron configuration?

76. • (b)
Iron is a transition metal. How is a transition element
identified from its electron configuration?
• incomplete d-subshell/ d-orbitals/ form an ion with outer electron(s) in
a d -sublevel
...3

77. • (b)
Iron is a transition metal. How is a transition element
identified from its electron configuration?
• incomplete d-subshell/ d-orbitals/ form an ion with outer electron(s) in
a d -sublevel
...3
State two characteristic properties of transition metals.
2×3

78. • (b)
Iron is a transition metal. How is a transition element
identified from its electron configuration?
• incomplete d-subshell/ d-orbitals/ form an ion with outer electron(s) in
a d -sublevel
...3
State two characteristic properties of transition metals.
2×3
variable valency, form coloured compounds, are good catalysts
any two...
2×3

79. • (b)
Iron is a transition metal. How is a transition element
identified from its electron configuration?
• incomplete d-subshell/ d-orbitals/ form an ion with outer electron(s) in
a d -sublevel
...3
State two characteristic properties of transition metals.
2×3
variable valency, form coloured compounds, are good catalysts
any two...
2×3
The metallic crystalline structure of iron is shown in Figure 12.
Describe the bonding in a metallic crystal.

80. • (b)
Iron is a transition metal. How is a transition element
identified from its electron configuration?
• incomplete d-subshell/ d-orbitals/ form an ion with outer electron(s) in
a d -sublevel
...3
State two characteristic properties of transition metals.
2×3
variable valency, form coloured compounds, are good catalysts
any two...
2×3
The metallic crystalline structure of iron is shown in Figure 12.
Describe the bonding in a metallic crystal.
positive ions in a sea of electrons/(valence) electrons involved in
delocalised bonding / free to move / released

82. • (c)
What type of bond exists in a water molecule?
polar
(covalent bond)
...3

83. • (c)
What type of bond exists in a water molecule?
polar
(covalent bond)
...3
State the shape of a water molecule and explain, using the
electron pair repulsion theory, how this shape arises.
4×3

84. • (c)
What type of bond exists in a water molecule?
polar
(covalent bond)
...3
State the shape of a water molecule and explain, using the
electron pair repulsion theory, how this shape arises.
4×3
v-shaped (planar) stated or shown in a diagram
...3
two lone pairs and two bond pairs stated or shown in clear
diagram
... bond angle reduced to 104.5o
lp lp > lp bp > bp bp

85. • (c)
What type of bond exists in a water molecule?
polar
(covalent bond)
...3
State the shape of a water molecule and explain, using the
electron pair repulsion theory, how this shape arises.
4×3
v-shaped (planar) stated or shown in a diagram
...3
two lone pairs and two bond pairs stated or shown in clear
diagram
... bond angle reduced to 104.5o
lp lp > lp bp > bp bp
What forces hold the water molecules together in an ice crystal?

86. • (c)
What type of bond exists in a water molecule?
polar
(covalent bond)
...3
State the shape of a water molecule and explain, using the
electron pair repulsion theory, how this shape arises.
4×3
v-shaped (planar) stated or shown in a diagram
...3
two lone pairs and two bond pairs stated or shown in clear
diagram
... bond angle reduced to 104.5o
lp lp > lp bp > bp bp
What forces hold the water molecules together in an ice crystal?
hydrogen bonds

87. • (c)
What type of bond exists in a water molecule?
polar
(covalent bond)
...3
State the shape of a water molecule and explain, using the
electron pair repulsion theory, how this shape arises.
4×3
v-shaped (planar) stated or shown in a diagram
...3
two lone pairs and two bond pairs stated or shown in clear
diagram
... bond angle reduced to 104.5o
lp lp > lp bp > bp bp
What forces hold the water molecules together in an ice crystal?
hydrogen bonds
What type of crystal lattice is formed in ice?

88. • (c)
What type of bond exists in a water molecule?
polar
(covalent bond)
...3
State the shape of a water molecule and explain, using the
electron pair repulsion theory, how this shape arises.
4×3
v-shaped (planar) stated or shown in a diagram
...3
two lone pairs and two bond pairs stated or shown in clear
diagram
... bond angle reduced to 104.5o
lp lp > lp bp > bp bp
What forces hold the water molecules together in an ice crystal?
hydrogen bonds
What type of crystal lattice is formed in ice?
molecular crystal

89. 2004 QUESTION 8

90. 2004 QUESTION 8
• (a) Explain the terms (i) energy level, (ii) orbital. (i) definite (discrete)
(specific) level of energy ...3 possessed by an electron in an atom
...3

91. 2004 QUESTION 8
• (a) Explain the terms (i) energy level, (ii) orbital. (i) definite (discrete)
(specific) level of energy ...3 possessed by an electron in an atom
...3
(ii) region in space around the nucleus ...3 where there is a high probability of
finding an electron ...3

92. 2004 QUESTION 8
• (a) Explain the terms (i) energy level, (ii) orbital. (i) definite (discrete)
(specific) level of energy ...3 possessed by an electron in an atom
...3
(ii) region in space around the nucleus ...3 where there is a high probability of
finding an electron ...3
What information about an electron in an atom is given by the principal
(first) quantum number and by the subsidiary (second) quantum number?
shell/main energy level / orbit (to which the electron belongs) ...3 type of
subshell / sublevel (to which an electron belongs) ...3

93. 2004 QUESTION 8
• (a) Explain the terms (i) energy level, (ii) orbital. (i) definite (discrete)
(specific) level of energy ...3 possessed by an electron in an atom
...3
(ii) region in space around the nucleus ...3 where there is a high probability of
finding an electron ...3
What information about an electron in an atom is given by the principal
(first) quantum number and by the subsidiary (second) quantum number?
shell/main energy level / orbit (to which the electron belongs) ...3 type of
subshell / sublevel (to which an electron belongs) ...3
In the relationship E2 – E1 = hf, which applies to atomic emission spectra,
what do E1 , E2 and f represent?

94. 2004 QUESTION 8
• (a) Explain the terms (i) energy level, (ii) orbital. (i) definite (discrete)
(specific) level of energy ...3 possessed by an electron in an atom
...3
(ii) region in space around the nucleus ...3 where there is a high probability of
finding an electron ...3
What information about an electron in an atom is given by the principal
(first) quantum number and by the subsidiary (second) quantum number?
shell/main energy level / orbit (to which the electron belongs) ...3 type of
subshell / sublevel (to which an electron belongs) ...3
In the relationship E2 – E1 = hf, which applies to atomic emission spectra,
what do E1 , E2 and f represent?
E1 energy of electron in lower / inner energy level ...3 E2 energy of excited
state/energy of electron in outer/ higher energy level ...3 f, frequency
(of photon) ...3

95. 2004 QUESTION 8
• (a) Explain the terms (i) energy level, (ii) orbital. (i) definite (discrete)
(specific) level of energy ...3 possessed by an electron in an atom
...3
(ii) region in space around the nucleus ...3 where there is a high probability of
finding an electron ...3
What information about an electron in an atom is given by the principal
(first) quantum number and by the subsidiary (second) quantum number?
shell/main energy level / orbit (to which the electron belongs) ...3 type of
subshell / sublevel (to which an electron belongs) ...3
In the relationship E2 – E1 = hf, which applies to atomic emission spectra,
what do E1 , E2 and f represent?
E1 energy of electron in lower / inner energy level ...3 E2 energy of excited
state/energy of electron in outer/ higher energy level ...3 f, frequency
(of photon) ...3
Name one metallic element whose salts give a lilac colour to a Bunsen burner
flame.

96. 2004 QUESTION 8
• (a) Explain the terms (i) energy level, (ii) orbital. (i) definite (discrete)
(specific) level of energy ...3 possessed by an electron in an atom
...3
(ii) region in space around the nucleus ...3 where there is a high probability of
finding an electron ...3
What information about an electron in an atom is given by the principal
(first) quantum number and by the subsidiary (second) quantum number?
shell/main energy level / orbit (to which the electron belongs) ...3 type of
subshell / sublevel (to which an electron belongs) ...3
In the relationship E2 – E1 = hf, which applies to atomic emission spectra,
what do E1 , E2 and f represent?
E1 energy of electron in lower / inner energy level ...3 E2 energy of excited
state/energy of electron in outer/ higher energy level ...3 f, frequency
(of photon) ...3
Name one metallic element whose salts give a lilac colour to a Bunsen burner
flame.
potassium

98. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3

99. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3

100. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3

101. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3

102. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.

103. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the

104. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]

105. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]

106. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom

107. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom
N = 1s2 2s2 2p3

108. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom
N = 1s2 2s2 2p3

109. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom
N = 1s2 2s2 2p3
Draw a diagram to show the valence electrons and the bonding in ammonia
(NH3). three single bonds ...3 one lone pair ...3 correct arrangement of atoms

110. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom
N = 1s2 2s2 2p3
Draw a diagram to show the valence electrons and the bonding in ammonia
(NH3). three single bonds ...3 one lone pair ...3 correct arrangement of atoms

111. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom
N = 1s2 2s2 2p3
Draw a diagram to show the valence electrons and the bonding in ammonia
(NH3). three single bonds ...3 one lone pair ...3 correct arrangement of atoms
Use electron pair repulsion theory to predict the shape of and the bond angle
in the ammonia molecule. pyramidal 107° (107.5°)

112. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom
N = 1s2 2s2 2p3
Draw a diagram to show the valence electrons and the bonding in ammonia
(NH3). three single bonds ...3 one lone pair ...3 correct arrangement of atoms
Use electron pair repulsion theory to predict the shape of and the bond angle
in the ammonia molecule. pyramidal 107° (107.5°)
bond pairs and 1 lone pair of electrons / lp:lp > lp:bp > bp:bp

113. • (b) Define electronegativity attraction an atom (element) has ...3 for a
shared pair of electrons ...3
Use electronegativity values to predict the type of bonding in ammonia. 3
polar covalent (bonding) ...3
Is ammonia soluble in water? Explain your answer in terms of bonding.
yes ...3 water is polar / there is an attraction between the water molecules and
the ammonia molecules / hydrogen bonds form between the water and the
ammonia molecules [like dissolves like unacceptable]
Write the electronic (s, p) configuration of the nitrogen atom
N = 1s2 2s2 2p3
Draw a diagram to show the valence electrons and the bonding in ammonia
(NH3). three single bonds ...3 one lone pair ...3 correct arrangement of atoms
Use electron pair repulsion theory to predict the shape of and the bond angle
in the ammonia molecule. pyramidal 107° (107.5°)
bond pairs and 1 lone pair of electrons / lp:lp > lp:bp > bp:bp

114. WHAT WE NEED TO KNOW
TO ANSWER QUESTION 8
• Bonding: Ionic, covalent, hydrogen and metallic
• Properties of different bonding types & Allotropes
• Electronegativity
• First ionisation energy
• Electron configuration
• E2-E1 = hf and quantum numbers
• VSEPR theory
• Transition metal properties

117. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3

118. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3

119. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3
• which an electron has (in an atom) …3

120. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3
• which an electron has (in an atom) …3
• (ii) region in space / around the nucleus / in an atom …3

121. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3
• which an electron has (in an atom) …3
• (ii) region in space / around the nucleus / in an atom …3
• where there is a high probability of finding an electron …3

122. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3
• which an electron has (in an atom) …3
• (ii) region in space / around the nucleus / in an atom …3
• where there is a high probability of finding an electron …3
• (i) How does an electron in an atom become excited?
3

123. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3
• which an electron has (in an atom) …3
• (ii) region in space / around the nucleus / in an atom …3
• where there is a high probability of finding an electron …3
• (i) How does an electron in an atom become excited?
3
• it gains energy / heat / place in a discharge tube …3

124. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3
• which an electron has (in an atom) …3
• (ii) region in space / around the nucleus / in an atom …3
• where there is a high probability of finding an electron …3
• (i) How does an electron in an atom become excited?
3
• it gains energy / heat / place in a discharge tube …3
• (ii) Why does the electron not remain in the excited
state? 3

125. • Explain the terms (i) energy level, (ii) atomic orbital.
4×3
• (i) definite (discrete) (specific) level of energy …3
• which an electron has (in an atom) …3
• (ii) region in space / around the nucleus / in an atom …3
• where there is a high probability of finding an electron …3
• (i) How does an electron in an atom become excited?
3
• it gains energy / heat / place in a discharge tube …3
• (ii) Why does the electron not remain in the excited
state? 3
• it is unstable / temporary / loses energy …3

127. • Question 8 (b)

128. • Question 8 (b)
• Define the first ionisation energy of an element.

129. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3

130. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3
• from a neutral / gaseous / isolated atom …3

131. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3
• from a neutral / gaseous / isolated atom …3
• State and explain the general trend in first ionisation energy
values down any group in the periodic table.

132. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3
• from a neutral / gaseous / isolated atom …3
• State and explain the general trend in first ionisation energy
values down any group in the periodic table.
• values decrease down a group …6

133. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3
• from a neutral / gaseous / isolated atom …3
• State and explain the general trend in first ionisation energy
values down any group in the periodic table.
• values decrease down a group …6
• due to increasing atomic radius /screening effect of inner
electrons …3

134. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3
• from a neutral / gaseous / isolated atom …3
• State and explain the general trend in first ionisation energy
values down any group in the periodic table.
• values decrease down a group …6
• due to increasing atomic radius /screening effect of inner
electrons …3
• Explain why the second ionisation energy of potassium
(3070 kJ mol–1) is significantly greater than its first
ionisation energy value (418 kJ mol–1).

135. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3
• from a neutral / gaseous / isolated atom …3
• State and explain the general trend in first ionisation energy
values down any group in the periodic table.
• values decrease down a group …6
• due to increasing atomic radius /screening effect of inner
electrons …3
• Explain why the second ionisation energy of potassium
(3070 kJ mol–1) is significantly greater than its first
ionisation energy value (418 kJ mol–1).
• second electron is taken from a full 3rd shell / energy level / inner
shell …6

136. • Question 8 (b)
• Define the first ionisation energy of an element.
• energy required to remove the most loosely bound / first /
outermost electron …3
• from a neutral / gaseous / isolated atom …3
• State and explain the general trend in first ionisation energy
values down any group in the periodic table.
• values decrease down a group …6
• due to increasing atomic radius /screening effect of inner
electrons …3
• Explain why the second ionisation energy of potassium
(3070 kJ mol–1) is significantly greater than its first
ionisation energy value (418 kJ mol–1).
• second electron is taken from a full 3rd shell / energy level / inner
shell …6
• [second electron removed from full p-orbital / more stable
configuration, one correct (s,p) configuration …3]

138. • level and the frequency of the electromagnetic radiation
emitted?

139. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6

140. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3

141. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?

142. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3

143. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3
• (v) Write the electronic (s, p) configuration of the potassium
ion, K+.

144. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3
• (v) Write the electronic (s, p) configuration of the potassium
ion, K+.
• 1s2 2s2 2p6 …3

145. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3
• (v) Write the electronic (s, p) configuration of the potassium
ion, K+.
• 1s2 2s2 2p6 …3
• 3s2 3p6 …3

146. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3
• (v) Write the electronic (s, p) configuration of the potassium
ion, K+.
• 1s2 2s2 2p6 …3
• 3s2 3p6 …3
• [ ]+ …3

147. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3
• (v) Write the electronic (s, p) configuration of the potassium
ion, K+.
• 1s2 2s2 2p6 …3
• 3s2 3p6 …3
• [ ]+ …3
• (vi) State the number of energy levels and the number of
orbitals occupied by the electrons in the potassium ion, K+.

148. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3
• (v) Write the electronic (s, p) configuration of the potassium
ion, K+.
• 1s2 2s2 2p6 …3
• 3s2 3p6 …3
• [ ]+ …3
• (vi) State the number of energy levels and the number of
orbitals occupied by the electrons in the potassium ion, K+.
• three energy levels …3

149. • level and the frequency of the electromagnetic radiation
emitted?
• E2 – E1 …6
• = hf …3
• (iv) Flame tests on metal salts are based on electron
transitions within atoms.What colour do potassium salts
give to a Bunsen flame?
• lilac / purple …3
• (v) Write the electronic (s, p) configuration of the potassium
ion, K+.
• 1s2 2s2 2p6 …3
• 3s2 3p6 …3
• [ ]+ …3
• (vi) State the number of energy levels and the number of
orbitals occupied by the electrons in the potassium ion, K+.
• three energy levels …3
• nine orbitals …3