Amerisyo

Americium, ₉₅Am

Americium
Bigkas	/ˌæməˈrɪsiəm/ ​(AM-ə-RISS-ee-əm)
Appearance	silvery white
Bilang na pangmasa	[243]
Americium sa talahanayang peryodiko
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Eu ↑ Am ↓ — plutonium ← americium → curium
Atomikong bilang (Z)	95
Group	n/a
Period	7
Block	f-block
Electron configuration	[Rn] 5f7 7s2
Electrons per shell	2, 8, 18, 32, 25, 8, 2
Physical properties
Phase at STP	solido
Melting point	1449 K ​(1176 °C, ​2149 °F)
Boiling point	2880 K ​(2607 °C, ​4725 °F) (calculated)
Density (near r.t.)	12 g/cm3
Heat of fusion	14.39 kJ/mol
Molar heat capacity	28 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 1239 1356
Atomic properties
Oxidation states	+2, +3, +4, +5, +6, +7 (isang anpoterong oksido)
Electronegativity	Pauling scale: 1.3
Ionization energies	1st: 578 kJ/mol
Atomic radius	empirical: 173 pm
Covalent radius	180±6 pm
Mga linyang espektral ng americium
Other properties
Natural occurrence	sintetiko
Crystal structure	​double hexagonal close-packed (dhcp)
Thermal conductivity	10 W/(m⋅K)
Electrical resistivity	0.69 µΩ⋅m
Magnetic ordering	paramagnetic
Molar magnetic susceptibility	+1000.0×10−6 cm3/mol
CAS Number	7440-35-9
History
Naming	after the Americas
Discovery	Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso (1944)
Isotopes of americium
Main isotopes Decay abun­dance half-life (t1/2) mode pro­duct 241Am synth 432.2 y α 237Np SF – 242m1Am synth 141 y IT 242Am α 238Np SF – 243Am synth 7350 y α 239Np SF –

Ang americium o amerisyo (Kastila: americio, may sagisag na Am, atomikong bilang na 95, espesipikong grabidad na 11.7, at balensiyang 3, 4, 5, at 6). Isa itong elementong metaliko, maputi, at trans-uraniko, na kabilang sa serye ng aktinido. Nagtataglay ito ng mga isotopong may bilang ng masa mula 237 hanggang 246. Mayroon itong mga hating-buhay mula 25 mga minuto hanggang 7,950 taon. Sa pananaliksik, pinagmumulan ito ng mga sinag-alpa, partikular na ang mga isotopong Am 241 at Am 243. Natuklasan ito nina Glenn Theodore Seaborg, Leon O. Morgan, Ralph A. James, Stanley G. Thompson, at Albert Ghiorso noong 1945.