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This article is about metallic materials. For other uses, see Metal (disambiguation).
圖片參考:
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Hot_metalwork.jpg/250px-Hot_metalwork.jpg
圖片參考:
http://en.wikipedia.org/skins-1.5/common/images/magnify-clip.png
Hot metal work from a blacksmith
In chemistry, a metal (Greek: Metallon) is an element that readily forms positive ions (cations) and has metallic bonds. Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons. The metals are one of the three groups of elements as distinguished by their ionization and bonding properties, along with the metalloids and nonmetals. On the periodic table, a diagonal line drawn from boron (B) to polonium (Po) separates the metals from the nonmetals. Most elements on this line are metalloids, sometimes called semi-metals; elements to the lower left are metals; elements to the upper right are nonmetals.
A modern definition of metals is that they have overlapping conduction bands and valence bands in their electronic structure. This definition opens up the category for metallic polymers and other organic metals, which have been made by researchers and employed in high-tech devices. These synthetic materials often have the characteristic silvery-grey reflectiveness of elemental metals.
The traditional definition focuses on the bulk properties of metals. They tend to be lustrous, ductile, malleable, and good conductors of electricity, while nonmetals are generally brittle (for solid nonmetals), lack lustre, and are insulators.
釙是一種化學元素,它的化學符號是Po,它的原子序數是84,是銀白色的類金屬。
釙的化學性質與硒及硫類似,但帶有放射性。
釙在1898年由居里夫人及她丈夫皮埃爾·居里發現。釙的拼音名稱是居里夫人紀念她的故鄉波蘭(Polska)而命名。
釙的特性
鉍 - 釙 - 砹
碲
釙
Uuh
圖片參考:
http://upload.wikimedia.org/wikipedia/commons/thumb/9/99/Po-TableImage.png/250px-Po-TableImage.png
元素周期表
總體特性
名稱, 符號, 序號
釙、Po、84
系列
類金屬
族, 周期, 元素分區
16族(VIA), 6, p
密度、硬度
9196 kg/m3、無數據
顏色和外表
銀色
地殼含量
- %
原子屬性
原子量
[209] 原子量單位
原子半徑(計算值)
190(135)pm
共價半徑
無數據
范德華半徑
無數據
價電子排布
[氙]4f145d106s26p4
電子在每能級的排布
2,8,18,32,18,6
氧化價(氧化物)
4,2(兩性)
晶體結構
單斜晶體
物理屬性
物質狀態
固態、放射性
熔點
527 K(254 °C)
沸點
1235 K(962 °C)
摩爾體積
22.97×10-6m3/mol
汽化熱
無數據
熔化熱
60.1 kJ/mol
蒸氣壓
0.0176 帕(527K)
聲速
無數據
其他性質
電負性
2.0(鮑林標度)
比熱
無數據
電導率
2.19×106/(米歐姆)
熱導率
20 W/(m·K)
第一電離能
812.1 kJ/mol
最穩定的同位素
同位素 豐度 半衰期 衰變模式 衰變能量
MeV 衰變產物
208Po
人造
2.898年
α衰變
電子捕獲
5.215
1.401
204Pb
208Bi
209Po
人造
103年
α衰變
電子捕獲
4.979
1.893
205Pb
209Bi
210Po
人造
138.376天
α衰變
5.407
206Pb