FOLLOW UP QUESTION-NUCLEI

1.  THERE ARE NO ELECTRON INSIDE THE NUCLEI.
          a) HOW CAN BETA PARTICLE OR AN ELECTRON COME FROM THE NUCLEUS
          b) HOW CAN GAMA RAY IS EMITTED FROM A NUCLEUS

2.  Q VALUE IS  THE ENERGY CORRESPONDING TO THE DIFFERENCE IN MASS OF THE REACTANT NUCLEONS MINUS THE MASS OF THE PRODUCT NUCLEI.
          a) IF Q VALUE IS POSITIVE,WHAT IS THE NATURE IS THE NUCLEAR REACTION.
          b) IF Q VALUE IS NEGATIVE WHAT IS THE NATURE OF THE NUCLEAR REACTION

3.   a)  IF THE MASS OF THE PRODUCT NUCLEI IS <THE MASS OF THE REACTANT NUCLEI ,WHAT IS THE SIGN OF Q
       b) IS ENERGY ISABSORBED OR RELEASED IN THE ABOVE CASE.

4.  IF 1 Kg  AND  I Gm OF THE SAME RADIOACTIVE MATERIAL ARE TAKEN SEPARATELY.
         a) WHAT IS THE MASS  LEFT AFTER A HALFLIFE
         b) WHAT IS THE MASS LEFT AFTER TWO HALF LIFE

5.   a)  IDENTIFY THE CHARGES ON RADIOACTIVE RAYS
      b) COMPARE THE MASSES OF THE PARTICLES OF THE RADIOACTIVE RAYS

6.  IT IS ESTIMATED THAT THE ENERGY RELEASED IN AN ATOM BOMB EXPLOSION HAS BEEN 7.6x10^13J. IF EACH FISSION RELEASES AN ENERGY OF 2000MeV,CALCULATE THE NUMBER OF ATOM FISSIONED

7.  FIND THE ENERGY IN eV EQUIVLENT TO 1 a.m.u OF MATTER

8.  WHICH ARE THE DIIFFERENT TYPES OF NUCLEAR REACTOR

9.  WHAT ARE THE MAIN PARTS AND FUNCTION OF THE NUCLEAR REACTOR

10.  a)  WHAT IS HALF LIFE PERIOD
       b)  HALF LIFE OF A 3 ELEMENTS ARE GIVEN IN THE TABLE.RANK THE ELEMENTS ACCORDING TO THEIR ACTIVITIES
       RADIUM                  -       1.6X10^3Y
       LANTHUM               -       1.1X10^10Y
       PHOSPHOROUS     -        14.3DAYS

11.  CLASSIFY THE FOLLOWING STATEMENT AS PROPERTIES OF ALPHA PARTICLE AND BETA PARTICLE
     PROPERTIES
  a)  THEY CAN INTERACT WITH ATOM AND AS A RESULT THEY GET SCATTERED WHILE TRAVELLING THROUGH MATTER.
 b) WHILE COMING OUT FROM NUCLEUS THEY SOMETIMES INTERACT WITH ORBITAL ELECTRONS & THEY EJECT SECONDARY ELECTRON FROM ORBIT
  c) THE ENERGY SPECTRUM APPEARS CONTINUOUS DUE TO THE CREATION OF VERY LIGHT PARTICLE CALLED NEUTRINO
   d) THE VELOCITY & K.E OF PARTICLE DEPENDS ON ENERGY OF THE PARENT WHICH EMITS THEM

12.  AN ATOMIC REACTOR IS YIELDING 30,000KW ENERGY PER SECOND. CALCULATE THE NUMBER OF URANIUM ATOM UNDERGO FISSION PER SECOND.GIVE THAT ENERGY PER FISSION IS 200 MeV.

QUESTIONS

1.PREDICT THE CONSEQUENCE OF NUCLEAR FISSION.
2.WHY ARE THE CONTROL RODS MADE OF CADMIUM.
3. WHY HEAVY WATER IS USED AS A MODERATOR.
4.NUCLEAR FUSION IS CALLED THERMONUCLEAR REACTION WHY?
5.HOW IS ENERGY PRODUCED IN STARS.
6.WHAT IS THE ORDER OF TEMPERATURE FOR FUSION REACTION

DIFFERENCE BETWEEN FISSION AND FUSSION

Nuclear Fission vs Nuclear Fusion

Natural occurrence of the process:Fission reaction does not normally occur in nature.Fusion occurs in stars, such as the sun.
Byproducts of the reaction:Fission produces many highly radioactive particles.Few radioactive particles are produced by fusion reaction, but if a fission "trigger" is used, radioactive particles will result from that.
Energy Ratios:The energy released by fission is a million times greater than that released in chemical reactions; but lower than the energy released by nuclear fusion.The energy released by fusion is three to four times greater than the energy released by fission.
Nuclear weapon:One class of nuclear weapon is a fission bomb, also known as an atomic bomb or atom bomb.One class of nuclear weapon is the hydrogen bomb, which uses a fission reaction to "trigger" a fusion reaction
Definition:Fission is the splitting of a large atom into two or more smaller ones.Fusion is the fusing of two or more lighter atoms into a larger one.
Conditions:Critical mass of the substance and high-speed neutrons are required.High density, high temperature environment is required.
Energy requirement:Takes little energy to split two atoms in a fission reaction.Extremely high energy is required to bring two or more protons close enough that nuclear forces overcome their electrostatic repulsion.

NUCLEAR FUSION

NUCLEAR FUSION

The process in which two or more light nuclei are combined into a single nucleus with the release of tremendous amount of energy is called as nuclear fusion. Like a fission reaction, the sum of masses before the fusion (i.e. of light nuclei) is more than the sum of masses after the fusion (i.e. of bigger nucleus) and this difference appears as the fusion energy. The most typical fusion reaction is the fusion of two deuterium nuclei into helium.
1H1 + 1H2 —> 2He4 + 21.6 MeV

For the fusion reaction to occur, the light nuclei are brought closer to each other (with a distance of 10–14 m). This is possible only at very high temperature to counter the repulsive force between nuclei. Due to this reason, the fusion reaction is very difficult to perform. The inner core of sun is at very high temperature, and is suitable for fusion, in fact the source of sun's and other star's energy is the nuclear fusion reaction

NUCLEAR REACTOR

An assembly in which a nuclear fission chain reaction is maintained and controlled for the production of nuclear energy, radioactive isotopes, or artificial elements. The nuclear fuel used in a reactor consists of fissile material (e.g. uranium-235 which undergoes fission as a consequence of which two nuclides of approximately equal mass are produced together with between two or three neutrons and a considerable quantity of energy. These neutrons cause further fissions so that a chain reaction develops. In order that the reaction should not get out of control, its progress is regulated by neutron absorbers in control rods, only sufficient free neutrons being allowed to exits in the reactor to maintain the reaction at a constant level. The fissile material is usually mixed with a moderator which slows down, or thermalizes, the fast neutrons emitted during fission, so that they are more likely to cause further fissions of the fissile material than they are to be captured by the uranium-238 isotope.

In a heterogeneous reactor the fuel and the moderator are separated in a geometric pattern called a lattice. In a homogeneous reactor the fuel and the moderator are mixed so that they present a uniform medium to the neutrons (e.g., the fuel, in the form of a uranium salt, may be dissolved in the moderator).

Besides this classification, reactors may be described in a number of ways. They may be described in terms of neutron energy (see fast reactor and thermal reactor) or in terms of function, e.g., a power reactor for generating useful electric power, a production reactor for manufacturing fissile material (see also breeder reactor and converter reactor) and a propulsion reactor for supplying motive power to ships, submarines, or spacecraft. Reactors are also described in terms of their fuel (e.g., plutonium reactor), their moderator (e.g. graphite-moderated reactor), or their coolant (e.g., boiling-water reactor).