KERALA PSC / CHEMISTRY / NUCLEAR CHEMISTRY / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY / NOTES

 

KERALA PSC / CHEMISTRY / NUCLEAR CHEMISTRY / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY / NOTES

KERALA PSC / CHEMISTRY / NUCLEAR CHEMISTRY / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY / NOTES

·      The branch of science which deals with the phenomenon of nuclei of atoms is known as nuclear chemistry

·      The phenomenon of spontaneous emission of active radiations from certain substances is called radioactivity and the substance emitting such radiations are called radioactive substances

·      Radio activity is classified into two types natural radioactivity and artificial radioactivity

·      If a substance emits radiations by itself, it is said to possess natural radio activity

·      If a substance does not posses radioactivity, but starts emitting radiation on exposure to rays from a natural radio active substance, it is said to posses induced or artificial radio activity

·      Under the influence of electric and magnetic field, the radioactive rays split into three kinds. They are names alpha (α), beta (β) and gamma (γ) rays

 

Properties of alpha rays:

·      Consists of positively charged particles

·      It is represented by ₂He⁴

·      Velocity of alpha particles is approximately ¹/₁₀ th of that of light

·      They can penetrate through thin metal foils

·      They cause ionization of gases

·      They can produce glow on a fluorescent screen

·      They affect photographic plates

 

Properties of Beta rays:

·      Consists of negatively charged particles

·      Beta particles are nothing but electrons

·      Velocity of Beta particles ranges between 33 and 99% of that of light

·      They have more penetrating power than alpha particles

·      They cannot ionize gases as strongly as α particles can

·      They can produce glow on a fluorescent screen

·      They affect photographic plates

 

Properties of gamma rays:

·      γ–rays are not deflected by magnetic or electric field.

·      They are not constituted of charged particles. Γ –rays are a form of powerful electro magnetic radiation of very short wavelength

·      Velocity of gamma rays equals that of light

·      They have much higher penetrating power than α and β rays

·      They can cause ionisation of gases

·      They produce glow on fluorescent screen

·      They affect photographic plates

 

Group Displacement Law:

·      “The emission of an α –particle by an element results in the formation of a new element which lies two places to the left of the parent element and the emission of a β –particle results in the formation of a new element which lies one place to the right of parent element in the periodic table”.

·      Decay constant (λ) may be defined as the fraction of the total number of radioactive atoms disintegrating in unit time.

·      Half-life period (t₁∕₂): The half-life period of a radioactive element is defined as the time required for the decay of one half of its original amount. t ₁∕₂ = 0.693 / λ

 

Artificial transmutation

·      The conversion of a stable nucleus into another nucleus by the bombardment of particles like protons, neutrons, α –particles etc… is known as artificial transmutation.

·      Nuclear fission discovered by Hahn and Strassman

·      Nuclear Fission is defined as the process of splitting of a heavy nucleus into two or more lighter nuclei by bombardment with a suitable sub-atomic particle.

·      The principle of atomic bomb is the uncontrolled nuclear chain reaction

·      Nuclear Fusion may be defined as a process in which two or more lighter nuclei combine to form a heavier nucleus

·      Nuclear fusion occurs only at very high temperatures which exist only in the interior of stars. The energy of sun is supposed to arise from nuclear fusion reaction

·      The nuclear fusion reaction is the basis of the hydrogen bomb

·      In carbon cycle the energy is produced by nuclear fusion

·      Radio carbon dating: is the technique of determining the age of old carbonaceous materials using the radio activity of carbon 14 isotopes

·      Radio carbon dating was developed by Willard F.Libby and he was awarded Nobel Prize for the same.

·      Natural radioactivity was discovered by Henry Bequerrel

·      Artificial Radioactivity was discovered by Irene Curie & F.Juliot

·      Simplest Radioactive atom is ₁H³ (Tritium)

·      Tritium is a beta emitter

·      The daughter element of Tritium is Helium – 3 (₂³He)

·      Age of fossil can be calculated by Radio-Carbon-Dating, using carbon-14.

·      Wine Dating can be done by using Tritium

·      Rock-Dating (Age of planet) can be calculated by Uranium dating by using U-238 and Pb-206.

·      Radioactive Iodine (Iodine – 131) is used for the treatment of Hyper Thyroidism

·      Cobalt – 30 isotope is used for cancer treatment

·      Deficit in blood-circulation is identified by using phosphorous – 32

·      Gold – 198 is used for the treatment of Leukemia

·      Angiogram Test is done by using sodium – 24

·      Bone cancer can be diagnosed by using phosphorous – 32

·      Highest velocity is shown by gamma rays (same as light)

·      Highest penetrating power is also shown by gamma rays due to very high energy (very short wavelength)

·      During beta emission isobars are produced

·      Controlled fission reaction is done in Nuclear Reactor

·      The coolants used in Nuclear Reactor is Liquid Sodium

·      Graphite Rods and Cadmium Rods are used as moderator in Nuclear Reactor

·      Five research reactor of India at BARC are Purnima, Zerlina, Dhruva, Circus and Apsara

·      Important Power stations in India are:

Ø Tarapur Atomic Power Station: Maharashtra

Ø Rajasthan Atomic Power station: Kota

Ø Narora Atomic Power Station: U.P

Ø Indira Gandhi Centre for atomic Research: Kalpakkam (Chennai)

·      World’s first fast breeder reactor named KAMINI – Kalpakam (Chennai|). The Kalpakkam reactor, has successfully used the mixed uranium – plutonium carbide fuel.

·      Strongest Radioactive element is RADIUM

·      Liquid Radioactive metal is FRANCIUM

·      Gaseous Radioactive element is RADON

·      Unit of Radioactivity is Bequerrel (Bq) (1 Bq = 1 disintegration per second),

1 curie = 3.7 ×10¹⁰ Bq

·      Photographic film is very strongly affected by beta rays

1 curie = 3.7 ×10¹⁰ dis/sec

1 Bequerrel = 1 dis/sec

1 Rutherford = 10⁶ dis/sec

·      Radioactive disintegration of uranium ultimately results in formation of lead.

 

KERALA PSC / CHEMISTRY / NUCLEAR CHEMISTRY / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY / NOTES