磷——发生、性质、用途、影响
磷是生命所必需的元素,主要是通过磷酸盐,磷酸盐是含有磷酸根离子的化合物。磷酸盐是 DNA、RNA、ATP 和磷脂的组成部分,所有这些都是细胞必需的复杂化合物。人尿是磷酸盐的最初供应源,骨灰是磷酸盐的重要早期来源。由于磷酸盐存在于动物遗骸和排泄物的化石沉积物中,因此磷酸盐矿含有化石。在一些水生系统中,低磷酸盐水平是一个重要的生长限制。提取的大部分磷化合物用于制造肥料。
虽然磷以两种主要形式存在,白磷和红磷,但由于其高反应性,它从未在地球上以游离元素的形式存在。它在地壳中的浓度约为每公斤一克。磷在矿物质中最常见的是磷酸盐。
Phosphorus is a chemical element with the atomic number 15 and the symbol P.
磷的出现
- 地壳中磷的浓度约为每公斤一克。它在自然界中不以纯净形式存在,但存在于多种矿物质中,最显着的是磷酸盐。
- 今天,这种元素的主要商业来源是无机磷矿石,其中含有一些磷灰石。
- 尿液、骨灰和鸟粪在历史上是主要的有机来源,但经济上的成功是有限的。
- 因为尿液中含有磷,所以它必须对今天仍在使用的特性进行施肥。
磷的性质
- 磷是一种氮族多价非金属。它在自然界中以几种同素异形体的形式存在,是生物体生存所必需的。
- 磷分为三种类型:白磷、红磷和黑磷,尽管它们的颜色更可能略有不同。
- 白磷是工业品种;它在黑暗中发光,暴露在空气中会自燃,是一种致命的毒药。
- 由于其化学结构的细微变化,红磷的颜色范围从橙色到紫色。
- 第三种形式,黑磷,是在高压下产生的,类似于石墨,并且像石墨一样可以导电。
磷的氧化状态
- 磷与氮一样,可以具有 +3 或 3 的氧化态,具体取决于与其结合的元素的电负性。
- 氮和磷的主要区别在于后者具有显着较低的电负性和较大的原子,具有可用的外 d 轨道。
- 由于这些原因,氮和磷化学之间的相似之处大多是形式上的,掩盖了实际的显着差异。
- 磷的外部 d 轨道允许八位字节扩展,导致 +5 状态,其中化合物中产生五个真正的共价键,这是氮无法达到的条件。
磷的用途
- 如今,常用的磷有四种:白色、黑色、红色和紫色。
- 磷很容易位于元素周期表的第 15 位,就在氮 (N) 的下方。
- 磷也存在于烟花爆竹、肥料和发酵粉中。
- 磷也用于钢铁制造。
- 磷酸盐还用于制造精美的瓷器和特殊玻璃。
Health Effects of Phosphorus
Phosphates are the most common form of phosphorus in the environment. Because phosphorus is a component of DNA and aids in energy delivery, it is a vital chemical in the human body. Phosphates are also found in a lot of plants.
Humans have significantly altered the natural phosphate supply by adding phosphate-rich manure to the soil and using phosphate-containing detergents. Phosphates are also found in a variety of foods, including cheese, sausages, and hams. Too much phosphate can harm your health by causing kidney damage and osteoporosis. Phosphate shortages are also possible. They are caused by long-term use of the medication. Phosphate deficiency is harmful to our health.
In its pure form, phosphorus is white. White phosphorus is the most dangerous phosphorus source we know of. When white phosphorus occurs naturally, it can be dangerous to our health. White phosphorus is extremely toxic and can be fatal in many cases.
磷的同素异形体
在自然界中,磷有多种同素异形体形式。白磷、黑磷和红磷是磷最重要的同素异形体。
白磷
白磷分子具有四面体结构,由四个原子组成。环应变和不稳定性是由四面体排列引起的。据说该分子由六个单 P-P 键组成。已知有两种结晶形式。阿尔法形式被定义为元素的标准状态,但它实际上在标准条件下是亚稳态的。
赤磷
红磷形式的磷是一种常见的同素异形体,被认为是 P 4分子的衍生物。它由无定形(非晶态)网络中的磷原子组成。已发现它比白磷(另一种天然存在的磷同素异形体)更稳定。红磷的深红色和粉状质地使其与众不同。白磷同素异形体逐渐转变为红磷同素异形体。在以热的形式存在光和能量的情况下,这种转变会加速。当白磷部分转化为红磷时,它呈现出独特的黄色外观。
示例问题
问题一:元素磷的用途是什么?
回答:
Phosphorus is an essential plant nutrient, and phosphate compounds primarily use it in the production of fertilizers. There is a phosphorus cycle, just as there are bio carbon and nitrogen cycles. Phosphorus is used in the production of red phosphorus safety matches, pyrotechnics, and inflammatory shells.
问题2:磷的主要来源是什么?
回答:
Phosphorus is found in high concentrations in protein foods such as milk and milk products, as well as meat alternatives such as beans, lentils, and nuts. Phosphorus is found in grains, particularly whole grains. Phosphorus is found in lower concentrations in vegetables and fruits.
问题 3:是什么让磷与众不同?
回答:
Except for black phosphorus, phosphorus is a poor conductor of heat and electricity. At room temperature, all forms of phosphorus are stable. The white allotrope (also known as yellow phosphorus) is similar to wax, the red and purple allotropes are non-crystalline solids, and the black allotrope is similar to graphite in pencil lead.
问题四:什么是红磷?
回答:
Red phosphorus is a common allotrope of phosphorus and is thought to be a derivative of the P4 molecule. It is made up of phosphorus atoms in an amorphous (non-crystalline) network. It has been discovered to be more stable than white phosphorus.
问题5:火柴棍中使用了哪种磷?
回答:
When you light the match, a small amount of red phosphorus on the striking surface is transformed to white phosphorus, which then ignites. The heat from this ignites the potassium chlorate, causing the match head to burst into flame.