| environ. |
element of group Group IV consists of two subgroups: group IVb, main group, and group IVa. Group IVa consists of titanium, zirconium, and hafnium which are generally classified as transition metals. The main group consists of carbonium, silicium, germanium, tin, and lead. The main valency of the elements is IV, and the members of the group show a variation from nonmetallic to metallic behaviour in moving down the group. The reactivity of the elements increases down the group from carbon to lead. All react with oxygen on heating (第四族元素，包含两个子族：主族4b及4a族。4a族包含通常被归为过渡金属元素的钛、锆和铪。4b族包含碳、硅、锗、锡、和铅。主要的价数是4价。此族排列从上方的非金属元素至下方的金属元素。元素的反应性由碳至铅递增，且所有元素皆可与氧在加热状况下反应。) |
