Nuclear notation and Binding energy

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• Nuclear notation and Binding energy
• Contents
• Atomic notation
• Isotopes
• Whiteboard
• Binding Energy
• AMU
• Making an atom
• Calculating binding energy
• Whiteboards
• The curve of binding energy and the strong
  nuclear force (or why there is a limit to the
  periodic table)

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Atomic notation
X Symbol (C, Au) A Atomic Mass Number
nucleons (Protons Neutrons) Z Atomic Number
protons
Carbon A 12, Z 6. neutrons?
TOC
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Isotopes
Carbon 12 has 6 Neutrons
Carbon 14 has 8 Neutrons Carbon 14 is an isotope
of Carbon Chemically the same Nuclear-lly
different (its unstable) C-14, C-12
TOC
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Whiteboards Atomic Notation 1 2 3 4 5
TOC
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What is the Atomic notation for tritium?
(tritium is an isotope of Hydrogen with 2
neutrons)
Hydrogen has a Z 1, A 1 p 2 n 3
W
3/1 H
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10 protons, 12 neutrons. What is its atomic
notation?
Z 10, A 10 12 22, element 10 is Ne
W
22/10 Ne
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How many neutrons in U 235? (235 A) (1)
U is element 92 235 - 92 143 neutrons
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143
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How many neutrons in Pb 208? (208 A) (1)
Pb is element 82 208 - 82 126 neutrons
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126
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How many neutrons in Kr 78? (1)
Kr is element 36 78 - 36 42 neutrons
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42
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Binding energy - the energy to take an atom apart
Unified Mass Units (u) C 12 (neutral atom)
12.0000000 u (defined) 1 u 1.6605 x 10-27 kg
931.5 MeV (show c 2.998x108 m/s) Electron
.00054858 u (not useful) Proton 1.007276 u (not
useful) H (neutral atom) 1.007825 u (very
useful) Neutron 1.008665 u (very useful)
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Binding energy - the energy to take an atom apart
H (neutral atom) 1.007825 u (very
useful) Neutron 1.008665 u (very useful) 1 u
931.5 MeV
To take an atom apart C 14 has a mass of
14.003242 u (p. 1064 in text) C 14 can be taken
apart into 6 H atoms 6(1.007825 u) (i.e. 6 p
6 e) 8 Neutrons 8(1.008665 u) Total taken
apart mass 6(1.007825 u) 8(1.008665 u) Total
taken apart mass 14.116270 u Mass defect
14.11627 u - 14.003242 u 0.113028 u 0.113028 u
- Represents energy needed to take atom
apart Binding energy (0.113028 u)(931.5 MeV/u)
105.3 MeV
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Binding energy - the energy to take an atom apart
H (neutral atom) 1.007825 u (very
useful) Neutron 1.008665 u (very useful) 1 u
931.5 MeV

• Binding energy in general
• Look neutral atom mass in Appendix F (p 1064)
• Break atom into H and n
• Subtract neutral atom mass from taken apart mass
• Multiply mass defect by 931.5 Mev/u

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Whiteboards Binding Energy 1 2 3
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What is the binding energy for Nitrogen 13? (Z
7) N 13 mass 13.005738 u H 1.007825 u
Neutron 1.008665 u 1 u 931.5 MeV
Atom mass 13.005738 7H 6n 7(1.007825 u)
6(1.008665 u) 13.106765 u Binding energy
(13.106765 - 13.005738)931.5 MeV/u 94.11 MeV
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94.11 MeV
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What is the binding energy for Carbon 12? (Z
6) C 12 mass 12.000000 u (duh?) H 1.007825
u Neutron 1.008665 u 1 u 931.5 MeV
Atom mass 12.000000 6H 6n 6(1.007825 u)
6(1.008665 u) 12.09894 u Binding energy
(12.098940 12.000000)931.5 MeV/u 92.16
MeV Binding energy per nucleon C 12 92.16/12
7.68 MeV/nucleon C 14 105.3/14 7.52
MeV/nucleon (less)
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92.16 MeV
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What is the binding energy for Carbon 10? (Z 6)
C 10 mass 10.231610 u H 1.007825 u Neutron
1.008665 u 1 u 931.5 MeV
Atom mass 10.231610 6H 4n 6(1.007825 u)
4(1.008665 u) 10.08161 u Binding energy
(10.08161 - 10.23161)931.5 MeV/u -139.7 MeV
(Carbon 10 does not exist)
W
-139.7