1、金属中延展性最好的是金（Au ） ，常温下导电好的依次是银（Ag ）,铜（Cu ）,金（Au） ，铝（Al）等； 2、金属有几种分类方法： 实用分类法：黑色金属：铁、铬、锰三种 有色金属：铝、镁、钾、钠、钙、锶、钡、铜、铅、锌、锡、钴、镍、锑、汞、镉、铋、金、银、铂、钌、铑、钯、锇、铱、铍、锂、铷、铯、钛、锆、铪、钒、铌、钽、钨、钼、镓、铟、铊、锗、铼、镧、铈、镨、钕、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥、钪、钇、钍。 还可以把金属分为： 常见金属：如铁、铝、铜、锌等 稀有金属：如锆、铪、铌、钽等； 1.轻金属。密度小于 4500 千克/立方米，如钛、铝、镁、钾、钠、钙、锶、钡等。 2.重金属。密度大于 4500 千克/米 3，如铜、镍、钴、铅、锌、锡、锑、铋、镉、汞等。3.贵金属。价格比一般常用金属昂贵，地壳丰度低（又称克拉克值(CLARKE value)，一种表示地壳中化学元素平均含量的数值） ，提纯困难，如金、银及铂族金属。 4.准金属元素。性质介于金属和非金属之间，如硅、硒、碲、砷、硼等。 5.稀有金属。包括稀有轻金属，如锂、铷、铯等； 6.稀有难熔金属，如锆、钼、钨等； 7.稀有分散金属，如镓、铟、锗、铊等； 8.稀土金属，如钪、钇、镧系金属； 9.放射性金属，如镭、钫、钋及锕系元素中的铀、钍等。铜良好导电导热性 钛轻巧，其合金坚硬，不易变形 钨耐高温，不易融化 锡无毒，耐腐 铝有延性和展性，在潮湿空气中能形成一层防止金属腐蚀的氧化膜。 铁坚硬，易生锈The best in ductility in the metal is gold (Au), in normal temperature, the conductivity followed by silver (Ag), copper ( Cu ), gold (Au), aluminum (Al), etc.There are several classification methods for metal:Practical classification method :Ferrous metals: iron , chromium, manganese, three non-ferrous metals: aluminum, magnesium, potassium, sodium, calcium, strontium, barium, copper, lead, zinc, tin, cobal, nickel, antimony, mercury, cadmium, bismuth, gold, silver, platinum, ruthenium, rhodium, palladium, osmium, iridium, beryllium, lithium, rubidium, cesium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, molybdenum, gallium, indium, thallium, germanium, rhenium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, thorium. Can also be divided into: metal metal neodymium.The metal can also be classify as:Common metals: iron, aluminum, copper, zinc Rare metals: such as zirconium, hafnium, niobium, tantalum, etc. By the density & rareness, which can classify as following.1) Light metal: density less than 4500 kg/m3, such as titanium, aluminum, magnesium, potassium, sodium, calcium, strontium, barium . 2) Heavy metals: density greater than 4500 kg/m3 , such as copper, nickel, cobalt, lead, zinc, tin , antimony, bismuth, cadmium, and mercury .3) Precious metals: expensive than the commonly used metals, the crustal abundance (also known as the Clarke value ( CLARKE value), a representation of the value of the average content of chemical elements in the crust), difficult to purification, such as gold, silver and platinum group metals. 4）Metalloid elements: properties between the metal and nonmetal, such as silicon, selenium, tellurium, arsenic, boron , etc. .5) Rare metals: including the rare light metal such as lithium, rubidium , cesium , etc.6) Rare and refractory metals: zirconium, molybdenum, tungsten, etc. 7) Rare scattered metals: gallium, indium, germanium, thallium, etc. 8) Rare earth metals: scandium, yttrium, lanthanide series metal9) Radioactive metals: radium, francium, polonium and actinides in uranium, thorium and so on.Some properties for the common using metals:Copper - good thermal conductivity Titanium - light, the alloy is hard, not easy to deformationTungsten - high temperature, difficult to melt Tin - non-toxic, corrosion-resistant Aluminum - ductility and malleability, in moist air to form a layer to prevent metal corrosion oxide film. Iron - hard, easy to rust