2. AATTOOMMIICC SSTTRRUUCCTTUURREE
INTRODUCTION
This Powerpoint show is one of several produced to help students
understand selected GCSE Chemistry topics. It is based on the requirements
of the AQA specification but is suitable for other examination boards.
Individual students may use the material at home for revision purposes and
it can also prove useful for classroom teaching with an interactive white
board.
Accompanying notes on this, and the full range of AS and A2 Chemistry
topics, are available from the KNOCKHARDY SCIENCE WEBSITE at...
www.knockhardy.org.uk/gcse.htm
All diagrams and animations in this Powerpoint are original and
created by Jonathan Hopton. Permission must be obtained for their
use in any commercial work.
All diagrams and animations in this Powerpoint are original and
created by Jonathan Hopton. Permission must be obtained for their
use in any commercial work.
3. AATTOOMMIICC SSTTRRUUCCTTUURREE
CCOONNTTEENNTTSS
• Rutherford’s experiment
• Structure of atoms
• Mass number and atomic number
• Atoms and ions
• Isotopes
• Electronic structures of the first 20 elements
4. THE SSTTRRUUCCTTUURREE OOFF AATTOOMMSS
Atoms have a small central nucleus, which is
made up of protons and neutrons.
Around the nucleus are the electrons.
Because electrons weigh very much less than
protons and neutrons, most of the mass of an
atom is concentrated in its nucleus.
6. AATTOOMMIICC SSTTRRUUCCTTUURREE
RUTHERFORD’S EXPERIMENT
Many scientists thought atoms were solid like a ‘plum pudding’.
Ernest Rutherford wanted to find out what atoms were like.
7. AATTOOMMIICC SSTTRRUUCCTTUURREE
RUTHERFORD’S EXPERIMENT
ALPHA (a)
PARTICLES
GOLD
ATOMS
Many scientists thought atoms were solid like a ‘plum pudding’.
Ernest Rutherford wanted to find out what atoms were like.
He fired positively charged ALPHA PARTICLES (helium nuclei) at a
very thin sheet of gold and detected what happened to their path.
8. ALPHA (a)
PARTICLES
MOST WENT
STRAIGHT
THROUGH
AATTOOMMIICC SSTTRRUUCCTTUURREE
RUTHERFORD’S EXPERIMENT
MOST WENT STRAIGHT THROUGH MOST OF AN ATOM IS SPACE
9. ALPHA (a)
PARTICLES
SOME WERE
DEFLECTED
AATTOOMMIICC SSTTRRUUCCTTUURREE
RUTHERFORD’S EXPERIMENT
SOME WERE DEFLECTED NUCLEUS IS POSITIVELY CHARGED
11. ALPHA (a)
PARTICLES
MOST WENT
STRAIGHT
THROUGH
SOME WERE
DEFLECTED
AATTOOMMIICC SSTTRRUUCCTTUURREE
RUTHERFORD’S EXPERIMENT
VERY FEW
BOUNCED
STRAIGHT
BACK
SUMMARY
MOST WENT STRAIGHT THROUGH
SOME WERE DEFLECTED
MOST OF AN ATOM IS SPACE
NUCLEUS IS POSITIVELY CHARGED
VERY FEW BOUNCED STRAIGHT BACK NUCLEUS IS RELATIVELY SMALL
12. THE SSTTRRUUCCTTUURREE OOFF AATTOOMMSS
The three important particles found in atoms are…
Particle Where it is found Relative
mass
Relative
charge
PROTON
NEUTRON
ELECTRON
Atoms have a small central nucleus, which is made up of protons
and neutrons and around which there are electrons.
13. THE SSTTRRUUCCTTUURREE OOFF AATTOOMMSS
The three important particles found in atoms are…
Particle Where it is found Relative
mass
Relative
charge
PROTON
NEUTRON
ELECTRON
14. THE SSTTRRUUCCTTUURREE OOFF AATTOOMMSS
The three important particles found in atoms are…
Particle Where it is found Relative
mass
Relative
charge
PROTON NUCLEUS 1 +1
15. THE SSTTRRUUCCTTUURREE OOFF AATTOOMMSS
The three important particles found in atoms are…
Particle Where it is found Relative
mass
Relative
charge
+1
1
PROTON
NEUTRON 0
1
NUCLEUS
NUCLEUS
16. THE SSTTRRUUCCTTUURREE OOFF AATTOOMMSS
The three important particles found in atoms are…
Particle Where it is found Relative
mass
Relative
charge
PROTON
NEUTRON
ELECTRON
+1
0
-1
1
1
Negligble
‘Very small’
NUCLEUS
NUCLEUS
IN SHELLS
AROUND THE
NUCLEUS
17. THE STRUCTURE OOFF AATTOOMMSS -- SSuummmmaarryy
The three important particles found in atoms are…
Particle Where it is found Relative
mass
Relative
charge
PROTON
NEUTRON
ELECTRON
+1
0
-1
1
1
Negligble
‘Very small’
NUCLEUS
NUCLEUS
IN SHELLS
AROUND THE
NUCLEUS
18. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
19. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
Symbol Atoms of an element are given a symbol
Some have one capital letter H, N, O, P, K
Some have two letters, the first He, Na, Mg Cu
one being a capital
Recently discovered high atomic Unh
number elements have been given
symbols with three letters
20. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
Symbol Atoms of an element are given a symbol
Some have one capital letter H, N, O, P, K
Some have two letters, the first He, Na, Mg Cu
one being a capital
Recently discovered high atomic Unh
number elements have been given
symbols with three letters
When necessary, the atomic number and the
mass number can be written alongside the symbol
21. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
23
11
Na
When necessary, the atomic number and the
mass number can be written alongside the symbol
22. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
23
11
Na
Mass Number (A)
PROTONS + NEUTRONS
Atomic Number (Z)
PROTONS
23. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
23
11
Na
Mass Number (A)
PROTONS + NEUTRONS
Atomic Number (Z)
PROTONS
THESE ALWAYS GO
TOGETHER – ANYTHING
WITH 11 PROTONS MUST
BE SODIUM
24. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
23
11
Na
Mass Number (A)
PROTONS + NEUTRONS
Atomic Number (Z)
PROTONS
25. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
23
11
Na
Mass Number (A)
PROTONS + NEUTRONS
Atomic Number (Z)
PROTONS
THERE WILL BE 12 NEUTRONS
IN THE NUCLEUS
23 – 11 = 12
26. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Atomic Number (Z) Number of protons in the nucleus of an atom
Mass Number (A) Sum of the protons and neutrons in the nucleus
23
11
Na
Mass Number (A)
PROTONS + NEUTRONS
Atomic Number (Z)
PROTONS
28. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
29. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
PROTONS 6 11 16 17 20
ELECTRONS 6 10 16 18 18
ATOM or ION?
30. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
PROTONS 6 11 16 17 20
ELECTRONS 6 10 16 18 18
ATOM or ION? ATOM ION ATOM ION ION
31. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
THE CHARGE ON AN ION DEPENDS ON THE RELATIVE
NUMBERS OF PROTONS AND ELECTRONS
32. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
THE CHARGE ON AN ION DEPENDS ON THE RELATIVE
NUMBERS OF PROTONS AND ELECTRONS
MORE ELECTRONS THAN PROTONS NEGATIVE
FEWER ELECTRONS THAN PROTONS POSITIVE
33. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
THE CHARGE ON AN ION DEPENDS ON THE RELATIVE
NUMBERS OF PROTONS AND ELECTRONS
MORE ELECTRONS THAN PROTONS NEGATIVE
FEWER ELECTRONS THAN PROTONS POSITIVE
34. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
THE CHARGE ON AN ION DEPENDS ON THE RELATIVE
NUMBERS OF PROTONS AND ELECTRONS
MORE ELECTRONS THAN PROTONS NEGATIVE
FEWER ELECTRONS THAN PROTONS POSITIVE
PROTONS 6 11 16 17 20
ELECTRONS 6 10 16 18 18
ATOM or ION? ATOM ION ATOM ION ION
CHARGE
35. AATTOOMMSS AANNDD IIOONNSS
ATOMS SAME NUMBER OF ELECTRONS AS PROTONS
IONS DIFFERENT NUMBER OF ELECTRONS AND PROTONS
THE CHARGE ON AN ION DEPENDS ON THE RELATIVE
NUMBERS OF PROTONS AND ELECTRONS
MORE ELECTRONS THAN PROTONS NEGATIVE
FEWER ELECTRONS THAN PROTONS POSITIVE
PROTONS 6 11 16 17 20
ELECTRONS 6 10 16 18 18
ATOM or ION? ATOM ION ATOM ION ION
CHARGE Neutral + Neutral - 2+
36. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Protons Neutrons Electrons Charge Atomic
Number
Mass
Number Symbol
A 19 21 19
B 20 0 40
C + 11 23
D 6 6 0
E 92 0 235
F 6 13
G 16 2- 16
H 27Al3+
37. MASS NUMBER AANNDD AATTOOMMIICC NNUUMMBBEERR
Protons Neutrons Electrons Charge Atomic
Number
Mass
Number Symbol
A 19 21 19 0 19 40 40K
B 20 20 20 0 20 40 40Ca
C 11 12 10 + 11 23 23Na+
D 6 6 6 0 6 12 12C
E 92 143 92 0 92 235 235U
F 6 7 6 0 6 13 13C
G 16 16 18 2- 16 32 32S2-
H 13 14 10 3+ 13 27 27Al3+
39. IISSOOTTOOPPEESS
Atoms of the same element can have different numbers of
neutrons.
These atoms are called ISOTOPES of that element.
40. IISSOOTTOOPPEESS
Atoms of the same element can have different numbers of
neutrons.
These atoms are called ISOTOPES of that element.
Isotopes of an element have SAME NUMBER OF PROTONS
DIFFERENT NUMBER OF NEUTRONS
41. IISSOOTTOOPPEESS
Atoms of the same element can have different numbers of
neutrons.
These atoms are called ISOTOPES of that element.
Isotopes of an element have SAME NUMBER OF PROTONS
DIFFERENT NUMBER OF NEUTRONS
or put another way SAME ATOMIC NUMBER
DIFFERENT MASS NUMBER
42. IISSOOTTOOPPEESS
Atoms of the same element can have different numbers of
neutrons.
These atoms are called ISOTOPES of that element.
Isotopes of an element have SAME NUMBER OF PROTONS
DIFFERENT NUMBER OF NEUTRONS
or put another way SAME ATOMIC NUMBER
DIFFERENT MASS NUMBER
ISOTOPES HAVE SIMILAR CHEMICAL PROPERTIES
62. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
+
ATOMIC NUMBER 1
GROUP 1
ELECTRONIC
CONFIGURATION
1
HYDROGEN
• atoms have the same number of electrons as protons
• electrons are found in shells (energy levels) around the nucleus
• electrons are put into the lowest energy level first
63. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
2+
ATOMIC NUMBER 2
GROUP 0
ELECTRONIC
CONFIGURATION
2
HELIUM
• the innermost shell can hold up to two electrons
64. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
3+
ATOMIC NUMBER 3
GROUP 1
ELECTRONIC
CONFIGURATION
2,1
LITHIUM
• each shell (energy level) can hold a maximum number of electrons
• the first one can only hold 2,so the next goes in the second shell
65. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
4+
ATOMIC NUMBER 4
GROUP 2
ELECTRONIC
CONFIGURATION
2,2
BERYLLIUM
• the second shell is gradually filled up until it has eight electrons
66. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
5+
ATOMIC NUMBER 5
GROUP 3
ELECTRONIC
CONFIGURATION
2,3
BORON
• the second shell is gradually filled up until it has eight electrons
67. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
6+
ATOMIC NUMBER 6
GROUP 4
ELECTRONIC
CONFIGURATION
2,4
CARBON
• the second shell is gradually filled up until it has eight electrons
68. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
7+
ATOMIC NUMBER 7
GROUP 5
ELECTRONIC
CONFIGURATION
2,5
NITROGEN
• the second shell is gradually filled up until it has eight electrons
69. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
8+
ATOMIC NUMBER 8
GROUP 6
ELECTRONIC
CONFIGURATION
2,6
OXYGEN
• the second shell is gradually filled up until it has eight electrons
70. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
9+
ATOMIC NUMBER 9
GROUP 7
ELECTRONIC
CONFIGURATION
2,7
FLUORINE
• the second shell is gradually filled up until it has eight electrons
71. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
10+
ATOMIC NUMBER 10
GROUP 0
ELECTRONIC
CONFIGURATION
2,8
NEON
• the second shell is now full
• full outer shells are characteristic of the unreactive NOBLE GASES
72. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
11+
ATOMIC NUMBER 11
GROUP 1
ELECTRONIC
CONFIGURATION
2,8,1
SODIUM
• as the second shell is full, electrons go into the third shell
• the third shell can hold up to a maximum of eight electrons
73. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
12+
ATOMIC NUMBER 12
GROUP 2
ELECTRONIC
CONFIGURATION
MAGNESIUM
2,8,2
74. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
13+
ATOMIC NUMBER 13
GROUP 3
ELECTRONIC
CONFIGURATION
2,8,3
ALUMINIUM
75. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
14+
ATOMIC NUMBER 14
GROUP 4
ELECTRONIC
CONFIGURATION
2,8,4
SILICON
76. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
15+
ATOMIC NUMBER 15
GROUP 5
ELECTRONIC
CONFIGURATION
PHOSPHORUS
2,8,5
77. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
SULPHUR (SULFUR)
F
Cl
He
Ne
Ar
Ca
16+
ATOMIC NUMBER 16
GROUP 6
ELECTRONIC
CONFIGURATION
2,8,6
78. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
ATOMIC NUMBER 17
GROUP 7
ELECTRONIC
CONFIGURATION
2,8,7
17+
CHLORINE
79. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
18+
ATOMIC NUMBER 18
GROUP 0
ELECTRONIC
CONFIGURATION
2,8,8
ARGON
• the third shell is now full
• full outer shells are characteristic of the unreactive NOBLE GASES
80. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
19+
ATOMIC NUMBER 19
GROUP 1
ELECTRONIC
CONFIGURATION
POTASSIUM
2,8,8,1
• as the third shell is full, electrons go into the fourth shell
81. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
20+
ATOMIC NUMBER 20
GROUP 2
ELECTRONIC
CONFIGURATION
CALCIUM
2,8,8,2
83. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
16+
ELECTRONS ?
PROTONS ?
ATOM / ION ?
ELEMENT ?
ANSWER ?
WHAT IS IT?
84. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
16+
ELECTRONS 16
PROTONS 16
ATOM / ION ATOM
ELEMENT SULPHUR
ANSWER S
WHAT IS IT?
85. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
19+
ELECTRONS ?
PROTONS ?
ATOM / ION ?
ELEMENT ?
ANSWER ?
WHAT IS IT?
86. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
19+
ELECTRONS 18
PROTONS 19
ATOM / ION POSITIVE ION
ELEMENT POTASSIUM
ANSWER K+
WHAT IS IT?
87. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
17+
ELECTRONS ?
PROTONS ?
ATOM / ION ?
ELEMENT ?
ANSWER ?
WHAT IS IT?
88. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
17+
ELECTRONS 18
PROTONS 17
ATOM / ION NEGATIVE ION
ELEMENT CHLORINE
ANSWER Cl¯
WHAT IS IT?
89. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
8+
ELECTRONS ?
PROTONS ?
ATOM / ION ?
ELEMENT ?
ANSWER ?
WHAT IS IT?
90. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
8+
ELECTRONS 10
PROTONS 8
ATOM / ION NEGATIVE ION
ELEMENT OXYGEN
ANSWER O2-
WHAT IS IT?
91. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
13+
ELECTRONS ?
PROTONS ?
ATOM / ION ?
ELEMENT ?
ANSWER ?
WHAT IS IT?
92. H
Li
Na
K
Be
Mg
B
Al
C
Si
N
P
O
S
AATTOOMMIICC SSTTRRUUCCTTUURREE
F
Cl
He
Ne
Ar
Ca
13+
ELECTRONS 10
PROTONS 13
ATOM / ION POSITIVE ION
ELEMENT ALUMINIUM
ANSWER Al3+
WHAT IS IT?