Atomic Structure 原子结构主要分为以下四个板块：

今天给大家带来的物理Alevel笔记是：Atomic Structure 原子结构---Rutherford Alpha Particle Scattering Experiment卢瑟福阿尔法粒子散射实验

Rutherford's alpha particle scattering experiment changed the way we think of atoms.

Before the experiment the best model of the atom was known as the Thomson or "plum pudding" model. The atom was believed to consist of a positive material "pudding" with negative "plums" distributed throughout.

卢瑟福的α粒子散射实验改变了我们对原子的思考方式。

在该实验之前，原子的最佳模型被称为汤姆逊或 "李子布丁 "模型。原子被认为是由一个正物质 "布丁 "和分布在各处的负 "李子 "组成。

Rutherford directed beams of alpha particles (which are the nuclei of helium atoms and hence positively charged) at thin gold foil to test this model and noted how the alpha particles scattered from the foil.

卢瑟福将阿尔法粒子（是氦原子的原子核，因此带正电）的光束射向薄金箔以测试这个模型，并注意到阿尔法粒子如何从金箔上散射。

Rutherford made 3 observations:

Most of the fast, highly charged alpha particles went whizzing straight through undeflected. This was the expected result for all of the particles if the plum pudding model was correct.Some of the alpha particles were deflected back through large angles. This was not expected.A very small number of alpha particles were deflected backwards! This was definitely not as expected. Rutherford later remarked "It was as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back at you!"

卢瑟福做了3项观察。

大多数快速、高电荷的α粒子直接呼啸而过，没有发生偏转。如果李子布丁模型是正确的，这就是所有粒子的预期结果。

一些α粒子通过大角度被偏转回来。这并不是预期的。

极少数的α粒子被向后偏转！这绝对不是预期的。这绝对不是预期的。卢瑟福后来说："这就像你向一张纸巾发射了一枚15英寸的炮弹，而它又向你射来一样不可思议！"

To explain these results a new model of the atom was needed.

为了解释这些结果，需要一个新的原子模型。

In this model the positive material is concentrated in a small but massive (lot of mass - not size) region called the nucleus. The negative particles (electrons) must be around the outside preventing one atom from trespassing on its neighbours space to complete this model. The diagram below will help you to understand the results of the experiment.

在这个模型中，正物质集中在一个称为原子核的小而大（质量大--不是大小）的区域。负粒子（电子）必须围绕在外面，防止一个原子侵入其邻居的空间，以完成这个模型。