

Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
The concept of beta particle and beta decay. It describes the three forms of beta decay, beta negative, beta positive, and electron capture. It also explains the process of beta negative and beta positive decay and how they result in a daughter nucleus. The document also mentions the discovery of positron emission by Irene and Frederic Joliot-Curie in 1934. a brief history of beta decay and its naming by Ernest Rutherford in 1899.
Typology: Lecture notes
1 / 2
This page cannot be seen from the preview
Don't miss anything!
Beta particle also called beta ray or beta radiation is a high-energy, high-speed electron or positron emitted during beta decay. There are three forms of beta decay beta negative, beta positive and electron capture. Negatively charged beta particle identical to electron. Positively charged beta particle identical to positron. In beta decay unstable atomic nuclei spontaneously dissipate excess energy and undergo a change of one unit of positive charge without any change in mass number. Beta decay was named by Ernest Rutherford [1899], He called the less penetrating rays alpha and more penetrating rays beta. More beta particles ejected at speed approaching that of light. Beta negative decay [electron emission decay] All atoms consist of nucleus containing neutrons and protons, surrounded by negative orbital electrons, these orbital electrons are not involved in the electron emission associated with beta decay. Negative beta emission occurs when the ratio of neutrons to protons in the nucleus is too high. Excess neutron transforms in to electron, antineutrino and a proton, that remains in the product nucleus. Negative beta decay results in daughter nucleus, the proton number which is one more than its parents, but the mass number remains same. Eg: H- 3 decays to He - 3
Proton in the parent nucleus decays in to a neutron that remains in the daughter nucleus, and the nucleus emit neutrino and a positron. Beta positive decay produces a daughter nucleus, atomic number of daughter nucleus one less then parent nucleus and mass number remains same. Positron emission first discovered by Irene and Frederic Joliot – curie in 1934.
Electron orbiting around the nucleus combine with a nuclear proton to produce a neutron. Mostly electron capture occurs from innermost or k shell of electrons around the atom, for this reason the process often called k capture. In electron capture atomic number decreases by one and mass number remains same. This is a process which competes with positron emission. Eg: Decay of Beryllium 7 to Lithium 7 [atomic number of beryllium is 4, atomic number of lithium 3] Auger electron Auger electrons are the electrons that are emitted when a electron from higher energy level falls in to a vacancy in a inner shell. The process usually occurs when the atom bombarded with high energy electrons. The collision ejects an inner shell electron and the inner shell vacancy filled by a high energy electron from outer shell.