Calculate the binding energy of a tritium nucleus, Calculate the binding energy of a tritium nucleus, 3311H, in H, in

Joules and eV Joules and eV Proton mass Proton mass = 1.67262 x 10= 1.67262 x 10-27 -27 kgkgNeutron mass Neutron mass = 1.67493 x 10= 1.67493 x 10-27 -27 kgkg

Tritium nucleus Tritium nucleus = 5.00641 x 10= 5.00641 x 10-27 -27 kgkg

Electron charge Electron charge = 1.6 x 10= 1.6 x 10-19 -19 CC

Do now:Do now:Wednesday, April 19, 2023

Hint:Hint:

Solution:Solution:

EEbindingbinding = m = mdeficitdeficitcc22

textbook, page 208textbook, page 208

1) Define binding energy per nucleon (p209)1) Define binding energy per nucleon (p209)

2) Sketch and describe the binding energy 2) Sketch and describe the binding energy curves (p209, 210)curves (p209, 210)

3) Describe nuclear fusion and fission 3) Describe nuclear fusion and fission in terms of binding energy per nucleon in terms of binding energy per nucleon (p210 – 213)(p210 – 213)

Today’s Learning OutcomesToday’s Learning Outcomes

Binding Energy per NucleonBinding Energy per Nucleon

Mass number50 100 150 200

Binding energy

per nucleon

(MeV)

2

4

6

856Fe

238U4He

7Li

Fusion Fission

Mass per NucleonMass per Nucleon

Nuclear FissionNuclear Fission Breaking large unstable nuclei into smaller onesBreaking large unstable nuclei into smaller ones

1 2350 92n U 141

56Ba9236Kr

103 n

Nuclear FissionNuclear Fission

When a large nucleus is split into smaller When a large nucleus is split into smaller fragments, the fragments have fragments, the fragments have less massless mass per nucleonper nucleon

The lost mass is The lost mass is released as energyreleased as energy in in the form of kinetic energy of neutrons and the form of kinetic energy of neutrons and gamma raysgamma rays

Nuclear FissionNuclear Fission

Only one Only one neutron is neutron is needed to needed to start the start the reaction, but reaction, but several are several are producedproduced

n

UBa Kr

n n n

UBa Kr

n n n

UBa Kr

n n n

UBa Kr

n n n

This can start a “This can start a “chain reactionchain reaction” if there is a ” if there is a “ “critical masscritical mass” of Uranium” of Uranium

Nuclear FissionNuclear Fission

If the chain reaction is controlled it can be used in a nuclear If the chain reaction is controlled it can be used in a nuclear reactorreactor

- control rods (made of cadmium) absorb neutrons and prevent the chain - control rods (made of cadmium) absorb neutrons and prevent the chain reaction occurring too rapidlyreaction occurring too rapidly

If it is uncontrolled it explodes as a nuclear or atomic bombIf it is uncontrolled it explodes as a nuclear or atomic bomb

Nucelar Fission and FusionNucelar Fission and Fusion

Mass number50 100 150 200

Binding energy

per nucleon

(MeV)

2

4

6

856Fe

238U4He

7Li

Fusion Fission

Nuclear FusionNuclear Fusion The joining of two small nuclei to form one larger oneThe joining of two small nuclei to form one larger one For example:For example:

This is the process that powers the sunThis is the process that powers the sun nHeHH 10

42

31

21

Nuclear FusionNuclear Fusion

Fusing two light atoms together results in Fusing two light atoms together results in a nucleus with a nucleus with less massless mass per nucleon per nucleon

The lost mass results in a The lost mass results in a release of release of energyenergy

Nuclear FusionNuclear Fusion

Fusion requires extreme temperature (eg Fusion requires extreme temperature (eg millions of degrees) to occur, and has not millions of degrees) to occur, and has not practically and economically been used in practically and economically been used in power generation (yet….)power generation (yet….)

Hydrogen bombs have been successfully Hydrogen bombs have been successfully made, but require a fission reaction to made, but require a fission reaction to provide the necessary temp.provide the necessary temp.

VideosVideos

Activity 12BActivity 12B

H/W books: Nuclear by Mon 16H/W books: Nuclear by Mon 16thth

Read Chapter 12 – Fission and Read Chapter 12 – Fission and FusionFusion