Radioactivity | Definition, types, Equation, Application
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Radioactivity |
The phenomenon of spontaneous disintegration of Unstable nucleus with emission of Alpha, Beta and Gamma ray's is known as Radioactivity.
What are the Radioactive Elements
- The Element or Substance Containing Unstable atomic nuclei is Consider to be a Radioactive Substance.
- In Periodic table, all the element having atomic number 83 or more are generally unstable in order to achieve stability. This heavy element are radioactive elements.
- Example: Uranium (U), Radium (Ra), Thorium (Th) etc.
What is Radioactivity
Radioactivity
is the phenomenon of spontaneous disintegration of the nucleus of an atom with
the emission of one or more radiation like Alpha particle, Beta particle and
Gamma Rays.
Unit :
S.I Unit of Radioactivity is Becquerel(Bq)
1Bequerel (Bq) = 1 Disintegration/second
S.I Unit of Radioactivity is Becquerel(Bq)
1Bequerel (Bq) = 1 Disintegration/second
Currie
The activity of Radioactivity sample is said to be one Curie.
1Curie(Ci)=3.7×1010decays/second
Rutherford
The activity of a radioactive sample is said to be a one Rutherford.
The activity of a radioactive sample is said to be a one Rutherford.
1Rutherford(Rd)=106decays/second
where,
t = the age of the rock or minerals specimen
lambda is the appropriate decay constant
D is the number of atoms of a daughter product today
P is the number of atoms of the Parent isotope today.
These are the
fission reaction which takes place in atom a large amount of heat energy is
produced and the Process continuous until entire amount of fissionable material
get exhausted. In Atom Bomb both enriched Uranium U235 and P239
are used.
Enriched Uranium U235
3. NPCIL - Kudankulam ( Tamil Nadu)
4. NPICL - Kaiga (Karnataka)
5. NPICL - Kakrapar Gujarat
6. NPICL - Kalpakkam Tamil Nadu
7. NPICL - Narora Uttar Pradesh
Radioactive Decay
it is the transformation process in which radioactive rays are emitted from the nucleus of the atom cannot be accelerated and Slow Down by any physical or chemical process.Radioactive decay law
According to this law, the rate of decay of Radioactive Atom at any instant is proportional to the number of Atom present at that instant.![]() |
Radioactivity decay law equation |
Where, Lambda is decay
constant and N is number of undisintegrated nucleus present in the sample at
any instant t.
Term’s Related to Radioactivity
Half-life Cycle
The life
of the half- life of a radioactive element is defined as the time taken for
half number of atoms of the element to disintegrate (or decay) or to become
stable.
Or we can also say that Half-life of radioactive element is defined as the time during which half the number of Atom present initially in the sample of the element decay
Or we can also say that Half-life of radioactive element is defined as the time during which half the number of Atom present initially in the sample of the element decay
Mean Life/ Average Life
- It is represented by (Tau)
- Average life of radioactive element can be obtained by calculating the total life time of all the atoms of the radioactive element and dividing it by the total number of Atom present initially in the sample of the element.
- Equation.
Mean life of Radioactive Elements
Time Required to Decay
Radioactive displacement law
- The law of radioactive displacement is also known as Fajan’s and Soddy law.
- This law describes which chemical element and isotopes created during the particular type of Radioactive Decay.
Types of Radioactive Decay
1. Alpha rays
- It is denoted by Alpha (α).
- Also Known as Double positively charged Helium atom.
- There are positively charged Helium nuclei.
- In Alpha Decay the mass number of the product Nucleus is four less than that of decaying during the Particular type of Radioactive decay.
AXZ = A-4YZ-2
+ 4He2 + q
- It is denoted by Beta (β).
- They are negatively charged particle which have a similar feature like electron.
- They have only charge but no mass.
- In Beta Decay, the mass number of product nucleus remains same but atomic number Increases or Decreases by One.
- It can further Classified in to two Categories.
1. Beta-minus decay
In beta-minus
decay, an Electron and an Antineutrino are created and emitted from the nucleus
via the reaction given below:
n = p + e-
+ q
AXZ = AYZ+1
+ 0e-1 + q
32P15 = 32S16
+ 0e-1 + q
2. Beta-Plus Decay
In beta-plus
decay, a positron and a neutrino are created and emitted from the nucleus via
the reaction given below:
p = n + e-
+ q
AXZ = AYZ-1
+ 0e+1 + q
22Na11 = 22Na10
+ 0e+1 + q
3. Gama ray's:
- It is denoted by Gama (γ).
- They are charge less Proton which are highly energetic they travel in the form of electromagnetic wave and has a speed equal to the light or due to high frequency.
- They are highly energetic and have highest penetrating power.
- A gamma ray is emitted when alpha or beta decays results in a daughter nucleus in an excited state. Atom then return to ground state by a single photon transition or successive transitions involving more than one photon.
**The emission of alpha, and beta is from the Nucleus result in the form of a difference element (Atomic number goes on decreasing) but, the emission of Gama Ray's doesn't have any role in the formation of different elements.
Application Of Radioactivity
1. GH-Counter:
The
Geiger Muller counter (or GH-Counter) is a device which can detect the presence
of radioactive substance and can also measure is radioactivity.
2. Carbon Dating
- Carbon-14 is made in the Upper atmosphere.
- The half-life of C-14 is 5730.
- As an age signature levels of C-14 in carbon-based artifacts are compared to modern levels.
- It is a technique of estimating the age of remains of plants living organisms. such as plant or animal by measuring radioactivity by Carbon-14.
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Carbon dating formula |
where,
t = the age of the rock or minerals specimen
lambda is the appropriate decay constant
D is the number of atoms of a daughter product today
P is the number of atoms of the Parent isotope today.
Nuclear Energy (Or Atomic energy)
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Mass defect Equation |
The energy produced by nuclear fission or fusion is known as a nuclear.
Energy in a nuclear reaction there is a loss of mass. This mass is converted into energy and is given by mass defect Equation.
Energy in a nuclear reaction there is a loss of mass. This mass is converted into energy and is given by mass defect Equation.
E=mc2
Where, 'E' is Energy and 'm' is mass loss.
It is a formula of atom bomb.
Transmutation of less stable nuclei into more tightly bound nuclei provides an excellent possibility of releasing nuclear energy.
Two distinct ways of obtaining energy from nucleus are given as below:
It is a formula of atom bomb.
Transmutation of less stable nuclei into more tightly bound nuclei provides an excellent possibility of releasing nuclear energy.
Two distinct ways of obtaining energy from nucleus are given as below:
- Nuclear Fission
- Nuclear Fusion
Nuclear Fission
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Nuclear Fission Reaction |
- It's the Breaking large atom into smaller atom.
- It is the phenomenon of splitting of a heavy nucleus into two (or more) smaller nuclei with the release of nuclear energy.
- For Nuclear Fission enriched Uranium (U235)and Plutonium (P239) are used.
Types of Nuclear Fission
There are types of nuclear fission
1. Control Nuclear Fission
2. Uncontrolled Nuclear Fission
1. Control Nuclear Fission
This type of fission takes place in a nuclear reactor. Where Fission
reaction is reduced and the energy produce can be used for producing
electricity. In a nuclear reactor in which Uranium U235 isotope
is used as a nuclear fuel.
Future of Nuclear Reactor
- Fission reaction takes place at a control rate.
- A moderator is used to slow down the speed of fast moving neutron Graphite or Heavy Water (D2O) is used as a moderator.
- A Control device is known as a control road are used to control the flow of neutron by observing them ( Boron and Cadmium roads are used as Control road).
- Control roads become a saturated with a neutron after definite period of time and hence need to be replaced after a certain period of time.
- Ordinary Water or Heavy water are used as a coolant.
2. Uncontrolled Nuclear Fission
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Atomic Bomb (Uncontrolled Fusion Reaction) |
Enriched Uranium U235
- Natural Uranium occur as U238 and 0.7% of U235.
- In which U238 is not fissionable. Therefore, U235 has to separated and concentrated for Nuclear Fission in uranium with large quantity or love u 235 and Concentrated for Nuclear Fission.
- Uranium with large Quantity U235 Isotopes is Called as enriched Uranium.
Nuclear Fusion
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Nuclear Fusion reaction |
Combining of smallest substance to form a bigger one is called
Nuclear Fission.
It’s the process of fusing of two (or more) lighter Nuclear to
form a single heavy nucleus. In this reaction also large amount of heat energy
is produced.
**Nuclear Fission takes place in a sun and star and it is one of the main source of their light and heat energy.
In hydrogen bomb Nuclear Fission reaction takes place (for
starting a fusion reaction a small amount of propane energy required. Which can
also be obtained by fission reaction fission reaction) act as a trigger for
starting a fission reaction.
List of Nuclear Power Plant In India
Type: Boiling
water reactor (BWR)
& Pressurized heavy water reactor (PHWR)
Total capacity: 1,400 MW
2. NPCIL - Rawatbhata (Rajasthan)
Type: Pressurized heavy water reactor (PHWR)
Total capacity: 1,180 MW
3. NPCIL - Kudankulam (
Type: Water-Water Energetic Reactor (VVER)-1000
Total capacity: 2,000 MW
4. NPICL - Kaiga (Karnataka)
Type: Pressurized heavy water reactor (PHWR)
Total capacity: 880 MW
5. NPICL - Kakrapar
Type: Pressurized heavy water reactor (PHWR)
Total capacity: 440 MW
6. NPICL - Kalpakkam
Type: Pressurized heavy water reactor (PHWR)
Total capacity: 440 MW
7. NPICL - Narora
Type: Pressurized heavy water reactor (PHWR)
Total capacity: 440 MW
*** NPICL : Nuclear Power Corporation of India Limited
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