americium

views updated Jun 08 2018

americium (symbol Am) Radioactive metallic element of the actinide series, first made (1944) by US nuclear chemist Glenn Seaborg (1912–99) and others by neutron bombardment of plutonium. It is used in smoke detectors, and Am241 is a source of gamma rays. Properties: at.no. 95; r.a.m. 243.13; r.d. 13.67; m.p. 995°C (1821°F); b.p. unknown; most stable isotope Am243 (half-life 7650 yr).

AM

views updated May 18 2018

AM • abbr. ∎  amplitude modulation. ∎  Master of Arts.

am

views updated Jun 27 2018

am / am/ • 1st person singular present of be.

Am

views updated May 29 2018

Am • symb. the chemical element americium.

AM

views updated May 21 2018

AM Abbreviation of amplitude modulation

am

views updated May 17 2018

am (Ger.). At the, on the, to the, by the, near the. As in Am Meer, by the sea.

am

views updated May 17 2018

am see BE.

am

views updated Jun 27 2018

am Physics, symbol for attometre(s)