what is the most common isotope of boron
Isotopes of boron Boron (5B) naturally occurs as isotopes 10and 11B, the latter of which makes up about 80% of natural boron. There are 14 radioisotopes that have been discovered, with mass numbers from 6 to 21, all with short half-lives, the longest being that of 8B, with a half-life of only 770 milliseconds (ms) and 12B with a half-life of 20.2 ms. All other isotopes have half-lives shorter than 17.35 ms, with the least stable isotope being 7B, with a half-life of 150 yoctoseconds (ys). Those isotopes with mass below 10 decay into helium (via short-lived isotopes of beryllium for 7B and 9B) while those with mass above 11 mostly become carbon.
Period 7 element All elements of period 7 are radioactive. This period contains the actinides, which contains the heaviest naturally occurring element, plutonium; subsequent elements must be synthesized artificially. Whilst the first five of these are now available in macroscopic quantities, most are extremely rare, having only been prepared in microgram amounts or less. The later, transactinide elements have only been identified in laboratories in batches of a few atoms at a time.