PHYS1171 Lecture Notes - Lecture 12: Ionizing Radiation, Mass Number, Beta Decay
Document Summary
Isotopes: same number of protons, but different number of protons. For example, the most common isotope of hydrogen (1 one extra neutron to the nucleus, we get the isotope called deuterium (2 neutrons to the nucleus, we get the isotope called tritium (3. Different isotopes are often expressed as their element name followed by their atomic mass number, for example carbon-12 (12. Alpha decay: helium nucleus: 2 protons and 2 neutrons. Beta decay: happens to a single particle inside the nucleus, 2 types: beta-minus and beta-plus. It is mediated by the weak nuclear force, and results in a nucleus with more stability. The gamma decay of radium-226 is expressed as: (if the nucleus of an atom is in an excited state, which can undergo gamma decay, it is labelled with a *) Quiz: the atomic number is different for different elements. False: the atomic mass number is different for different isotopes of an element.
