High Quality Content by WIKIPEDIA articles! Naturally occurring erbium (Er) is composed of 6 stable isotopes, 162Er, 164Er, 166Er, 167Er, 168Er, and 170Er with 166Er being the most abundant (33.503% natural abundance). 30 radioisotopes have been characterized with between 74 and 109 neutrons, or 142 to 177 nucleons, with the most stable being 169Er with a half-life of 9.4 days, 172Er with a half-life of 49.3 hours, 160Er with a half-life of 28.58 hours, 165Er with a half-life of 10.36 hours, and 171Er with a half-life of 7.516 hours. All of the remaining radioactive isotopes have half-lives that are less than 3.5 hours, and the majority of these have half-lives that are less than 4 minutes. This element also has 13 meta states, with the most stable being 167mEr (t? 2.269 seconds). Данное издание представляет собой компиляцию сведений, находящихся в свободном доступе в среде Интернет в целом, и в информационном сетевом ресурсе "Википедия" в частности. Собранная по частотным запросам...