Explain Q - Value and, Threshold energy | Nuclear Chemistry | Physical Chemistry скачать в хорошем качестве

Explain Q - Value and, Threshold energy | Nuclear Chemistry | Physical Chemistry

1. Q Value: Those reactions in which nucleus of the atom of an element is involved is known as nuclear reaction. The energy change associated with any nuclear reaction is expressed in terms of one nuclear chemistry factor is known as Q and the value is known as Q - Values. Target + Projectile = Recoil Target + Ejected Particles. As the target is not moving, so it has only one type of energy and it is because of mass ({ m }_{ 0 }). Projectiles have two types of energy one because of mass ({ m }_{ 1 }) and other K.E. ({ E }_{ 1 }) therefore Total energy of projectile is ({ m }_{ 1 } + { E }_{ 1 }). Similarly total energy of recoil target is ({ m }_{ 2 } + { E }_{ 2 }) and that of ejected particles will be ({ m }_{ 3 } + { E }_{ 3 }) On substituting these values in above nuclear reaction, we get: ({ m }_{ 0 }) + ({ m }_{ 1 } + { E }_{ 1 }) = ({ m }_{ 2 } + { E }_{ 2 }) + ({ m }_{ 3 } + { E }_{ 3 }) ({ m }_{ 0 } + { m }_{ 1 }) + { E }_{ 1 } = ({ m }_{ 2 } + { m }_{ 3 }) + ({ E }_{ 2 } + { E }_{ 3 }) ({ m }_{ 0 } + { m }_{ 1 }) - ({ m }_{ 2 } + { m }_{ 3 }) = ({ E }_{ 2 } + { E }_{ 3 }) - { E }_{ 1 } But energy of products - Energy of reactant ({ E }_{ 2 } + { E }_{ 3 }) - { E }_{ 1 } is known as Q value, therefore Q = { m }_{ reactants } - { m }_{ products } = Delta m (atomic mass unit) therefore Q = Delta m times 931 (MeV) When Q is positive the energy is evolved. The reaction is Exoergic. But when Q is negative the reaction is said to be Endoergic. 2. Threshold Energy (Eth) : When the Q is negative, the nuclear reaction is said to be endoergic. For endoergic reaction to take place, the energy is to be supplied, now the question is how this energy must be supplied? As the energy of the target cannot be increased, the only possibility, the energy of projectiles can be increased in the form of acceleration. The part of the energy of the projectiles is utilised for maintaining the momentum of the recoil nucleus. The minimum amount of energy, that is necessary for endoergic reaction is called threshold energy. ({ E }_{ th }). It is found that { E }_{ th } = Qleft[ 1+frac { { m }_{ P } }{ { m }_{ T } } right] Where { m }_{ P } is mass of projectiles and { m }_{ T } is mass of target. Analytical Reasoning    • Solve Problems Related To Ages With These ...   English Grammar    • Making Sense With Tense #1 - English Grammar   Interview Skills    • Questions You May Be Asked During an Inter...   Managerial Economics    • MCQ #1 of Managerial Economics   Royalty Free Stock Footage    • Flowers - Royalty free footage   Chemical Thermodynamics - Physical Chemistry    • State and Explain first law of thermodynam...   Ionic Equilibria - Physical Chemistry    • Derive expression for Ostwald’s Dilution law.   Electrochemistry - Physical Chemistry    • What are different types of Reversible Ele...   Solid State - Physical Chemistry    • Explain the following terms | Solid State ...   Gaseous State - Physical Chemistry    • Postulates of Kinetic Molecular Theory of ...   Colloidal States - Physical Chemistry    • What is Colloidal Solution? | Colloidal St...   Stereochemistry - Organic Chemistry    • Explain Configuration and Conformation | S...   Nanomaterials - Engineering Chemistry    • Compare top down with bottom up Processes ...   Water and Its Treatment - Engineering Chemistry    • Explain why hard water gives out a curd li...   Electrochemistry - Engineering Chemistry    • Distinguish between metallic and electroly...   Environmental Studies    • MCQ on Environmental Studies Part 8   Optics - Applied Physics    • What are cartesian sign conventions for sp...   For Details Visit http://cepekmedia.co.nf http://cepek.hol.es/ http://edmerls.66Ghz.com/ http://edmerls.tk/