Calcium

解释

n.Symbol Ca （名词）符号 Ca
A silvery, moderately hard metallic element that constitutes approximately 3 percent of the earth's crust and is a basic component of most animals and plants. It occurs naturally in limestone, gypsum, and fluorite, and its compounds are used to make plaster, quicklime, Portland cement, and metallurgic and electronic materials. Atomic number 20; atomic weight 40.08; melting point 842 to 848=C; boiling point 1,487=C; specific gravity 1.55; valence 2.See table at element
钙：一种银色的、硬度适中的金属元素，约占地壳中各种元素的百分之三，是多数动物和植物的基本组成物之一。自然存在于石灰石、石膏、氟石以及其它化合物之中，用于制造石膏、生石灰、硅酸盐水泥以及冶金和电子材料。原子序数20；原子量40.08；熔点842到848度；沸点1,487度；比重1.55。