A lot vs. Alot: 9 Grammatical Pitfalls
A synthetic, radioactive element that is produced by bombarding bismuth with iron ions. Its most long-lived isotopes have mass numbers of 266 and 268 with half-lives of 3.4 milliseconds and 70 milliseconds, respectively. Atomic number 109. See Periodic Table.
an artificially produced element belonging to the transuranium group, atomic number 109. It is predicted to have chemical properties resembling those of iridium.