Nuclear Chemistry. Flashcards
What can you say about alpha decay?
Alpha decay causes decrease of atomic number by 2 units and mass number by 4 units. All nucleides with atomic number greater than 73 are beyond the band of stability are radioactive.
What can you say about beta decay?
Beta decay causes increase of atomic number by 1 unit and no change in mass number. A neutron is converted to proton in the process. Such emission occur for nuclei lying above the stability belt.
Why can you say about Gamma decay ?
Gamma Ray emission cause no change in the atomic number or mass number , since it represents the energy lost.
What can you say vanity positron emission?
Positron emission causes decrease in the atomic number by 1 unit. A proton is converted to Neuton and positron in this process. Such emission occur for nuclei lying below the stability belt.
What is a positron?
Positron is a particle having the same mass as an electron, but positively charged.
What can you say about electron capture?
Electron capture causes decrease in the atomic number by 1 unit. A proton is converted into a Neutron in this process. It occurs with nuclei lying below the stability belt, in which electron from the k shell is captured by the Nucleus.
What can you say about Group Displacement Law( Soddy Fajans )?
Alpha particle emission causes shift two places left in the periodic table. Beta particle emission causes shift one place to the right in the periodic table.
What can you say about neutron/proton ratio and stability zone?
For Z 1.5, nucleus is unstable. For Z> 83, there is no stable nuclei.
What do you know about Magic number and nuclear stability?
Nuclei with 2,8,20,28,50,82, or 126 protons or neutrons are unusually stable and have a large number of stable isotopes than other nuclei in the periodic table. These number are called magic numbers.
What is radioactive decay?
Radioactive decay is a prat order process. The rate of nuclear decay is determined from measurement of activity of the sample.
-dN/dt= lamda N
Lamda = decay constant.
SI unit is Becquerel= 1 disintegration per second.
What is mass defect?
Actual mass of an isotope is less than originally estimated because of loss of mass during its formation. This is called mass defect.
What are isotopes ?
Atoms with the same number of protons but different numbers of neutrons are called isotopes.
What are isobars?
Isobars are the atoms with the same value of mass number ( neutrons + protons ) are called isobars.
What are mirror nuclei ?
Two atoms X and Y are mirror nuclei of each other if X and Y are isobars.
What are Isotones ?
Isotones are atoms with the same number of neutrons
