Kesium

Kesium tabi kaesium je apilese kemika pelu ami-idamo Cs ati nomba atomu 55.

Caesium, ₅₅Cs

Caesium
Pípè	/ˈsiːziəm/ ​(SEE-zee-əm)
Ìhànsójú	silvery gold
Ìwúwo átọ̀mù Ar, std(Cs)	132.90545196(6)
Caesium ní orí tábìlì àyè
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 Rb ↑ Cs ↓ Fr xenon ← caesium → barium
Nọ́mbà átọ̀mù (Z)	55
Ẹgbẹ́	group 1: H and alkali metals
Àyè	àyè 6
Àdìpọ̀	Àdìpọ̀-s
Ẹ̀ka ẹ́límẹ́ntì	Alkali metal
Ìtò ẹ̀lẹ́ktrọ́nù	[Xe] 6s1
Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan	2, 8, 18, 18, 8, 1
Àwọn ohun ìní ara
Ìfarahàn at STP	solid
Ìgbà ìyọ́	301.59 K ​(28.44 °C, ​83.19 °F)
Ígbà ìhó	944 K ​(671 °C, ​1240 °F)
Kíki (near r.t.)	1.93 g/cm3
when liquid (at m.p.)	1.843 g/cm3
Critical point	1938 K, 9.4 MPa
Heat of fusion	2.09 kJ/mol
Heat of	63.9 kJ/mol
Molar heat capacity	32.210 J/(mol·K)
pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 418 469 534 623 750 940
Atomic properties
Oxidation states	−1, +1 Àdàkọ:Infobox element/symbol-to-oxidation-state/comment
Electronegativity	Pauling scale: 0.79
Atomic radius	empirical: 265 pm
Covalent radius	244±11 pm
Van der Waals radius	343 pm
Spectral lines of caesium
Other properties
Natural occurrence	primordial
Crystal structure	​(bcc)
Thermal expansion	97 µm/(m·K) (at 25 °C)
Thermal conductivity	35.9 W/(m·K)
Electrical resistivity	205  Ω·m (at 20 °C)
Magnetic ordering	paramagnetic
Young's modulus	1.7 GPa
Bulk modulus	1.6 GPa
Mohs hardness	0.2
Brinell hardness	0.14 MPa
CAS Number	7440-46-2
Main isotopes of caesium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct 133Cs 100% 133Cs is stable with 78 neutrons 134Cs syn 2.0648 y ε 1.229 134Xe β− 2.059 134Ba 135Cs trace 2.3×106 y β− 0.269 135Ba 137Cs trace 30.07 y β− 1.174 137Ba