A lot vs. Alot: 9 Grammatical Pitfalls
A synthetic, radioactive element that is produced by bombarding bismuth with chromium ions. Its most long-lived isotopes have mass numbers of 261, 262, and 264 with half-lives of 11.8 milliseconds, 0.1 second, and 0.44 second, respectively. Atomic number 107. See Periodic Table.
a synthetic element in Group VIIb of the periodic table. It is thought to be chemically similar to the rare metal rhenium.