Radiomu

Rédíọ́mù (pípè /ˈradiəmu/, RAY-dee-əm) jẹ́ ìpilẹ̀ṣẹ̀ kẹ́míkà tó ní àmì-ìdímọ̀ Ra àti nọ́ḿbà átọ̀mù 88.

Radium, ₈₈Ra

Radium
Pípè	/ˈreɪdiəm/ ​(RAY-dee-əm)
Ìhànsójú	silvery white metallic
nọ́mbà ìsújọ	[226]
Radium 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 Ba ↑ Ra ↓ Ubn francium ← radium → actinium
Nọ́mbà átọ̀mù (Z)	88
Ẹgbẹ́	group 2 (alkaline earth metals)
Àyè	àyè 7
Àdìpọ̀	Àdìpọ̀-s
Ẹ̀ka ẹ́límẹ́ntì	Alkaline earth metal
Ìtò ẹ̀lẹ́ktrọ́nù	[Rn] 7s2
Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan	2, 8, 18, 32, 18, 8, 2
Àwọn ohun ìní ara
Ìfarahàn at STP	solid
Ìgbà ìyọ́	973 K ​(700 °C, ​1292 °F)
Ígbà ìhó	2010 K ​(1737 °C, ​3159 °F)
Kíki (near r.t.)	5.5 g/cm3
Heat of fusion	8.5 kJ/mol
Heat of	113 kJ/mol
pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 819 906 1037 1209 1446 1799
Atomic properties
Oxidation states	+2 Àdàkọ:Infobox element/symbol-to-oxidation-state/comment
Electronegativity	Pauling scale: 0.9
Covalent radius	221±2 pm
Van der Waals radius	283 pm
Color lines in a spectral range Spectral lines of radium
Other properties
Natural occurrence	from decay
Crystal structure	​(bcc)
Thermal conductivity	18.6 W/(m·K)
Electrical resistivity	1 µ Ω·m (at 20 °C)
Magnetic ordering	nonmagnetic
CAS Number	7440-14-4
Main isotopes of radium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct 223Ra trace 11.43 d alpha 5.99 219Rn 224Ra trace 3.6319 d alpha 5.789 220Rn 226Ra ~100% 1602 y alpha 4.871 222Rn 228Ra trace 5.75 y beta− 0.046 228Ac