NUCLEAR ENERGY

Nuclear Energy:
This is the energy that is released during nuclear activities.
In nuclear reaction, the masses of the products are usually different from the masses of the 4 reactants.


Nuclear energy equation :
 ∆E = ∆mc–²
 where ∆E is energy released or energy change
∆m = is mass defect / change in mass and c is the velocity.

Electron Volt (EV):
Electron volt is the energy pocess by an electron that is moving under the influence of a potential difference of one volt. It is the unit of energy in nuclear energy.

Value of electron volt (ev):
1ev = 1.602 x 10 –¹9 Joule
1Mev = 1.602 x 10~¹9 Joule x 10~6  =  1.602 x 10~¹³ Joule

Atomic mass unit ( à.m.u.)
The unit of energy is also expressed in a.m.u.

Value of a.m.u:
1a.m.u = 931Mev which will be 931 x 1.602 x 10~¹³ Joule
              = 1491.462 Joules

Worked Examples:
1. Calculate the energy of 2.25ev.
Solution:
1ev = 1.602 x 10~¹9
Therefore,
   2.25ev will equal 2.25 x 1.602 x 10~ ¹9 = 3.6045 x 10~¹9 Joules

2. What is the value of 3.43 Joules in a.m.u?

Solution:
1 a.m.u = 931Mev = 931 x 1.602 x 10~¹³  = 3.6045 = 10~¹9 Joules
Therefore,
6874.23 x 10~¹9 Juole = 3.43 X 10~¹9 / 3.6045 x 10~¹9
                             = 0.952 a.m.u

Binding Energy:
It is the amount of energy that is required to split nucleon
( neutron and proton) in the nucleus of an atom.

When the proton and neutron are spitted, the total mass is usually less than the mass of the nucleus.
Therefore,
Binding energy can also be called mass difference of nucleus and nucleon.

FORMULA FOR CALCULATING BINDING ENERGY
Binding energy = mass of nucleus – mass of nucleons

Worked Examples:


TYPES OF NUCLEAR REACTIONS
Nuclear Fussion:
This is the type of nuclear reaction that involves the combination of two or more light or smaller nuclei at high temperature to form a heavier or bigger  nucleus and energy is released.
Examples of nuclear fusion: thermonuclear fusion equation
Magnesium is bombarded with helium to form silicon and energy is released
Boron is bombarded with hydrogen to form carbon and energy is released
Tritium is bombarded with hydrogen to form helium and energy is released
Tritium is bombarded with deuterium to form helium, proton and energy is released.
Remember to write the typical equation for each

Nuclear Fission:
This is the type of nuclear reaction that involves the splitting of heavy nucleus of a radioactive element into smaller nuclei of different masses by bombarding it with fast moving particle such as neutron, proton, electron, etc.

Examples of nuclear fission equation
Na + n ➡  Na ➡ Mg + e + Energy

Sodium is bombarded with proton to form unstable sodium  with mass numbe 24, which further split to magnesium, electron and energy is released


U +  n  ➡ U (unstable) ➡ Ba + Kr + 2n + energy
When Uranium is bombarded with proton, it form unstable uranium with mass number 236, which further split to barium, kripton, two atoms of proton.

Chain Reaction:
Tis is the type of nuclear reaction whereby nucleus of a radioactive element is split into tow or more nuclei and each nuclei in turn are split into many nuclei and the process keep on repeating itself, by bombarding the nucleus with a with fast moving proton. It is the multiple action of nuclear fission.
Diagram to illustrate chain reaction

Application of chain reaction:
Chain reaction is used in principle of operations of bomb.

Diagram of a nuclear reactor:


Explanation of parts:
Graphite:
It is used to moderate the speed of the neutron so that the chain reaction is prevented from dying out.

Boron steel rod:
It absorb excess neutron and control the number of neutron so that too many neutron would not increase the reaction and make to be out of control.
Electric motor:
The electric motor help to move the rod in and out of the reactor to a suitable position. If there is electrical failure, the rod would fall and shot down the reactor automatically.

Concrete Biological Shield:
It prove t the operator from intense radiation inside the core.

Characteristics of Nuclear Activity:
There is always a slight loss of mass in the reaction
Alpha, beta ,gamma particles and energy are emitted
New elements are always formed
The properties of the elements are always different from that of the parents elements
Radioactive elements decay with a specific half-life

Peaceful application of atomic energy:
It is used in Tue generate electricity
It is used in the produce nuclear weapons
It is used in the detect leakages or holes in pipes
It is used to detect hidden weapons
It is used in radiotherapy to detect broken bones
It is used to power nuclear plants
It is used as fuel
It is used in food preservation

Advantages of nuclear fusion over nuclear fission:
In nuclear fusion,
Power can be generated
Lightest elements can be used
The raw materials are cheap
Less dangerous by-products are produced
There is no maximum limit of hydrogen that can be obtained
Disadvantages of nuclear fusion over nuclear fission:
The binding energy needed for the reaction is greater than the energy produced or released
It is cost to run
It takes longer time

More problems:



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