radioactivity - the process by which an unstable nucleus emits one or more particles or energy in the form of electro-magnetic radiation, nuclear radiation - the particles that are released from the nucleus during radioactive decay, alpha particle - a positively charged atom that is released in the disintegration of radioactive elements and that consists of two protons and two neutrons, beta particle - a charged electron emitted during certain types of radioactive decay, such as beta decay, gamma ray - the high-energy photon emitted by a nucleus during fission and radioactive decay, half-life - the time required for half of a sample of a radioactive substance to disintegrate by radioactive decay or by natural processes, fission - the process by which a nucleus splits into two or more fragments and releases neutrons and energy, nuclear chain reaction - a continuous series of nuclear fission reaction, critical mass - the minimum mass of a fissionable isotope that provides the number of neutrons needed to sustain a chain reaction, fusion - the process in which light nuclei combine at extremely high temperatures, forming heavier nuclei and releasing energy, background radiation - the nuclear radiation that arises naturally from cosmic rays and from radioactive iso-topes in the soil and air, rem - the quantity of ionizing radiation that does as much damage to human tissue as 1 roentgen of high-voltage x-rays does, radioactive tracer - a radioactive material that is added to a substance so that its distribution can be detected later,

ch. 9

بواسطة
طباعة
تضمين

لوحة الصدارة

النمط البصري

الخيارات

تبديل القالب

استعادة الحفظ التلقائي: ؟