"Henri Becquerel (1852-1908) discovered radioactivity in 1896 when studying potassium uranyl sulfate 2. Further early advances were made by wife and husband, Marie Skłodowska Curie (1867-1934) and Pierre Curie (1859–1906), who were co-awarded the Nobel Prize in Physics with Becquerel in 1903. It was Marie Curie who coined the term radioactivity 4."
Expected headings
"Nuclei stability"
"Modes of decay"
"There are four fundamental forces of nature, namely: electromagnetic, weak, strong, and gravity. Inside a nucleus, the strong force is the principal force that holds the nucleons (protons and neutrons) together while the electromagnetic force acts as a repulsive force due to positive charges of protons. The proportions of the strong and electromagnetic forces affect the binding energy of the nucleus 5."
"When the mass number increases, the ratio of neutrons to protons also increases in order to maintain the nuclei stability. For example, helium-4 has a neutron to proton ratio of 1. For indium-115, the neutron to proton ratio increased to 1.35, while uranium-238 has neutron to proton ratio of 1.59 5. There are several "magic numbers" for protons and neutrons that give stability to the nucleus. For example, nuclei that have either 2, 8, 20, 28, 50, and 82 protons or neutrons are stable. In addition to these, nuclei with 126 and 184 neutrons or 114 protons are also stable 8. Thus, the nucleons that deviates from this band of stability will decay in various modes 5. Alpha decay occurs if there are too many nucleons, beta minus decay occurs when there are too much neutrons and beta plus decay occurs when there are too few neutrons or too much protons. The weak nuclear force mediates the transformation of a proton to a neutron and vice versa in a beta decay."
"When the mass number increases, the ratio of neutrons to protons also increases in order to maintain the nuclei stability. For example, helium-4 has a neutron to proton ratio of 1. For indium-115, the neutron to proton ratio increased to 1.35, while uranium-238 has neutron to proton ratio of 1.59 5. There are several "magic numbers" for protons and neutrons that give stability to the nucleus. For example, nuclei that have either 2, 8, 20, 28, 50, and 82 protons or neutrons are stable. In addition to these, nuclei with 126 and 184 neutrons or 114 protons are also stable 8. Thus, the nucleons that deviates from this band of stability will decay in various modes 5. Alpha decay occurs if there are too many nucleons, beta minus decay occurs when there are too much neutrons and beta plus decay occurs when there are too few neutrons or too much protons. The weak nuclear force mediates the transformation of a proton to a neutron and vice versa in a beta decay."