Nuclear Chemist

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79 Nuclear Chemist Questions And Answers

41⟩ Explain me what is the nature of radiation? Is it that people have no way to experience it?

No, it isn't. And radiation, of course, to most who work with it is a very workaday kind of thing. The nature of radiation is that it requires a good bit of it to do you any harm. The nature of radiation is that you can detect absolutely insignificant amounts of it, extremely easily. The nature of radiation is that if you don't choose to detect it, you have it falling on you from everywhere you are on the earth's surface, in amounts that are probably 100 times or 1,000 times more than you would ever get from living near a nuclear plant.

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43⟩ Tell me is it fair to compare American reactors to the one at Chernobyl?

It's completely unfair. It's like comparing the Stanley steamer that's going along at 150 miles an hour to a present day car with all the safety features a modern car has. And that Chernobyl plant was a very crude plant, was operating badly. It had the worst possible accident. And yet the number of identifiable deaths from it are really only a handful. And even the children who were affected by it, some few dozen, those could have been avoided with iodine tablets.

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46⟩ Explain us through the principal ways this energy's been harnessed, both in bomb making and in a controlled reaction?

In a controlled reaction you assemble uranium in a way that allows a very stable, very steady reaction. The heat gets produced, then is used to boil water and produce steam, and that steam then produces electricity through turbines, same as any other electrical generating plant. There's nothing very exotic really about it. The trick in all of it is to assemble that uranium in a manner that is the safest possible, and uses the resource most efficiently. And you want to see the waste from it minimized and be as safe as possible.

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47⟩ Explain different rules used for filling of orbitals in atoms?

☛ a. Aufbau Principle: According to this principle, In the ground state of an atom the electrons are added one by one to the various orbitals in order of their increasing energy starting with the orbitals of lowest energy. The order of increasing energies of various orbitals can be calculated by the (n+1) rule. However if the (n+1) value of two different orbitals are same then the orbitals with lower value of n has lower energy.

☛ b. Pauli Exclusion Principle: This principle states that an orbital can have maximum two electrons and these must have opposite spins.

☛ c. Hund’s rule of maximum multiplicity: Electron pairing in p, d and f orbitals cannot occur until each orbital of a given subshell contains one electron or is singly occupied. This happens because electrons being identical in charge repel each other when present at the same orbital.

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48⟩ Explain me radioactivity? Explain α, β and γ rays?

☛ a. The emission of radiation by uranium and its compound is an atomic phenomenon. It is independent of the chemical and physical state of the element. Such phenomenon is known as radioactivity and such elements are said to be radioactive.

☛ b. α rays: These rays consist of particles which are positively charged. If an a particle is emitted by the radioactive parent element then formation of the daughter element takes place which have atomic number less by 2 units and mass number less by 4 units.

☛ c. β rays: These rays consist of electrons. When the conversion of a neutron into proton takes place then an electron is ejected out, along with electron another particle is also ejected out which is known as anti-neutron. The mass of this anti-neutron in negligible. When a β ray is emitted by the parent element then the atomic number of the daughter is more by one unit than the parent element. However the mass number of both remains the same.

☛ d. γ rays: These rays are similar to electromagnetic radiation and possess very short wavelength. The daughter nucleus formed generally exists in the excited state. While returning to the ground state they generally emit its excess energy as γ-ray photon. Here the atomic number and the mass number of the daughter nucleus remains the same as of the parent nucleus.

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49⟩ Please explain what is the difference between fractionation and distillation?

Both methods are used to separate the components present in the solution based on the melting points

☛ Distillation : This technique is used when boiling point of chemicals are different in the mixtures

☛ Fractionation : This technique is used when boiling point of chemicals are close to each other in the mixtures

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50⟩ Explain me what is oxidation and reduction reaction?

Oxidation = When there is a loss of hydrogen or electrons, OR gain of oxygen is known as Oxidation reaction.

Reduction = When there is a gain of hydrogen or electron OR loss of oxygen is known as reduction reaction

Example of oxidation-reduction reaction is observed in human body, when an electron is transferred into the cell and oxidation of glucose take place from which we get the energy.

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51⟩ Explain heinsenberg’s uncertainty principle?

This principle states that it is impossible to measure simultaneously the position and momentum of a small particle with absolute accuracy or certainty. If an attempt is made to measure any one of these two quantities with higher accuracy, then the other becomes less accurate. The product of uncertainty in the position and uncertainty in momentum is always constant and is equal to or greater than h/4p i.e.

Δx. Δp = h/4π

Where,

h is the Planks constant

Δx is the uncertainty in position

Δp is the uncertainty in momentum

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52⟩ Explain me was Chernobyl a serious accident?

Chernobyl was the most serious accident, in my view, that a reactor could possibly have. It was a very large plant. It had been operating long enough that it had a large inventory of radioactive material and, it blew up. It was opened to the atmosphere for days. Fire, plumes of material, radioactive materials. The people who were asked to deal with the fire obviously had to be subjected to, in the crude way that the authorities responded to it, killing amounts of radiation. Some 30 or 40 of them did that, at an awful price. But contrary to the common knowledge that is simply not so. There have been very few, or in fact, only one identifiable source of deaths from that Chernobyl accident. And they are thyroids in children.

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53⟩ Tell me how is the isotopic form unsuitable for weapons?

Yes. Plutonium is different from uranium. Uranium has really those two isotopes. And let me call them by their names, uranium-235 and uranium-238. That's simply two different isotopes of the same metal. 235 is fissionable. Plutonium, when it's produced in a reactor, the first isotope you get is plutonium-239. That comes from the uranium-238. Almost immediately after that isotope will absorb another neutron and become plutonium-240. At least, some fraction of it will. And that is a highly unsatisfactory isotope to the weapons designer, because that gives off a lot of neutrons itself, and makes it very difficult to trigger any kind of an explosion effectively. But it goes right on. It goes to plutonium-241, to plutonium-242, and that whole mixture of isotopes of plutonium is exactly what the bomb designer does not want. He wants pure plutonium-239. That comes from reactors that are specially set up to produce the isotope plutonium-239, and not all of the mixture of isotopes that come out of the nuclear reactor.

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54⟩ Tell me what is range and specific ionisation of the emitted particles?

The radiations emitted by the radioactive nuclei are highly energetic and due to this the radiations can penetrate through the matter. The depth of these penetrations into the matter is proportional to the density of the matter. The distance covered by these radiations in the matter is called their range. The number of ion pairs per unit distance, the emitted particle covers in a medium is known as specific ionisation.

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55⟩ What is principal Quantum Number?

It is denoted by n. It tells us about the energy level or shell in which the electron is present. The value of n can be 1,2,3,4…….etc. but it cannot be zero. It gives us the information about the average distance of electrons from the nucleus, determines the energy of electron in hydrogen atom and hydrogen like atoms. It also gives us the information about the maximum number of electrons that a shell can have by using the formula 2n2.

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56⟩ What is uranium, and where does it come from?

Uranium is simply a metal. It's found everywhere in the earth's surface. It's found at two parts per billion in the oceans. It's concentrated, like all the metals, in deposits here and there all over the earth. It looks something like lead. It's heavy like lead. It has a mild amount of radioactivity associated with it, but nothing like radium, for example, which is also scattered throughout the earth's crust.

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58⟩ Tell me what is a half-life of plutonium?

Well, plutonium-239 has, for example, a roughly 25,000-year half-life. That is to say, half of it will have decayed to something else after 25,000 years, approximately. And that's a good long time. And the other isotopes that are similar to that, some have longer half-lives, some of them shorter. The point is that they are the most toxic elements in the waste. And paradoxically, they are also the most useful, because they are all fissionable. So they can be used to produce energy. But if they are there in the waste, they represent a long-term hazard that people can legitimately be concerned about. And those states that are being asked to accept the nuclear waste can legitimately be concerned about that. You know, I think again it's a handle-able problem, but it's a problem that needn't be there, for if you recycle, you separate out exactly those elements and use them in your reactor. You produce energy with them and they're gone. And the nuclear waste that is then put in the ground has a life of perhaps a few hundred years, and all of the really toxic materials are gone. So it totally changes the character of the nuclear waste problem.

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60⟩ Explain me what is dextro-rotatory and levo-rotatory?

Levorotation and Dextrorotation is referred to the properties of plane polarized light, when light rotates clockwise when it approaches the observer is then known as dextro-rotation and when the light rotates anti-clockwise then it is referred as levo-rotation.

A compound which exhibits a dextro-rotation is referred as dextro-rotatory and which exhibits levo-rotation is referred as levo-rotatory.

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