激进和离子
自由基和离子是活性物质。两者都是由比离子或自由基更稳定的中性原子或分子产生的。
激进的
自由基是一种具有未配对电子的原子、分子。换句话说,它们是开壳结构,正因为如此,自由基非常不稳定,所以反应活性很高。因此,它们的寿命很短。当自由基与另一种物质碰撞时,它们倾向于以一种导致未配对电子配对的方式发生反应。他们可以通过从另一个分子中获得一个原子来实现这一点。这个原子会给自由基一个电子,让它和未配对的电子配对。然而,由于这个原因,另一个自由基形成了(给前一个自由基提供原子的物种现在变成了一个自由基)。自由基发生反应的另一种方式是与含有多个键的化合物结合,产生一个更大的新自由基。当共价键被均裂(参与成键的两个电子平分给两个原子,这样一个原子只得到一个电子)时,自由基就形成了。要使共价键均裂,必须提供能量。 This is done in two ways, by heating or by irradiating with light. For example, peroxides produce oxygen radicals when they are subjected to heat. Normally when radicals are formed, they undergo a chain of reactions producing more and more radical. A chain reaction of a radical can be divided into three parts as initiation, propagation and termination. To stop a radical reaction (termination), two radicals should be joined together to form a covalent bond back. Radical reactions are important in many industrial processes. Radicals are used to produce plastics or polymers such as polythene. They are also important for the combustion processes by which the fuels are converted to energy. In living systems, radicals are always produced as intermediates in metabolism. However, radicals are considered as harmful within living systems. They can cause aging, cancer, atherosclerosis, etc. Therefore, in terms of medicine, radicals are also important.
离子
离子是带正电荷或负电荷的带电物质。带正电的离子称为阳离子,带负电的离子称为阴离子。当形成一个阳离子时,这个原子的一个电子会释放出来。形成阴离子时,原子得到一个电子。因此,在一个离子中,电子和质子的数量是不同的。离子可以带-1或+1电荷,我们称之为一价离子。同样地,还有二价离子、三价离子等。由于阳离子和阴离子带有相反的电荷,它们会被静电力吸引,形成离子键。阳离子通常由金属原子形成,阴离子由非金属原子形成。例如,钠是1族金属,因此形成+1的阳离子。 Chlorine is a nonmetal and has the ability to form a -1 charged anion.
自由基和离子有什么区别? 离子是一种获得额外电子或给出一个电子的物质。自由基是一种具有未配对电子的物质。 离子带正电荷或负电荷。自由基可以带正电荷、负电荷,也可以不带电荷。 |
留下一个回复