Looking Inside the Atom | 原子内部探秘

📚 Looking Inside the Atom | 原子内部探秘

All matter is built from atoms, but the atom itself has an intricate internal structure. For CIE A-Level Physics, “looking inside the atom” means understanding the nucleus, the particles that make it up, the forces holding it together, and the decays and reactions that release nuclear energy.

所有物质都由原子构成，但原子本身具有复杂的内部结构。在 CIE A-Level 物理中，“原子内部探秘”意味着理解原子核、组成它的粒子、维持它稳定的作用力，以及释放核能的衰变和反应。

1. The Nuclear Model of the Atom | 原子的核式模型

Rutherford’s alpha-particle scattering experiment showed that most of the atom is empty space, with almost all mass and all positive charge concentrated in a tiny central nucleus. Electrons orbit this nucleus at relatively large distances.

卢瑟福的 α 粒子散射实验表明，原子内部绝大部分是空的，几乎所有质量和全部正电荷都集中在一个微小的中心原子核中。电子在离核较远的地方绕核运动。

The nuclear diameter is about 10⁻¹⁵ m to 10⁻¹⁴ m, while the atomic diameter is about 10⁻¹⁰ m. This means the nucleus is about 10,000 to 100,000 times smaller than the atom.

原子核的直径约为 10⁻¹⁵ m 到 10⁻¹⁴ m，而原子直径约为 10⁻¹⁰ m。这意味着原子核比原子小约 1 万到 10 万倍。

2. Protons, Neutrons and Electrons | 质子、中子与电子

The nucleus contains protons and neutrons, collectively called nucleons. A proton carries charge +e, where e = 1.60 × 10⁻¹⁹ C, while a neutron is electrically neutral. Electrons carry charge −e and orbit the nucleus.

原子核包含质子和中子，统称为核子。质子带电荷 +e（e = 1.60 × 10⁻¹⁹ C），中子不带电。电子带电荷 −e，绕原子核运动。

The proton and neutron masses are nearly equal (about 1.67 × 10⁻²⁷ kg), whereas the electron mass is only about 1/1836 of a proton’s mass.

质子和中子的质量几乎相等（约为 1.67 × 10⁻²⁷ kg），而电子质量仅为质子质量的约 1/1836。

A nuclide is described by its proton number Z and nucleon number A. The number of neutrons is therefore N = A − Z.

核素用质子数 Z 和核子数 A 来描述。因此中子数为 N = A − Z。

3. Nuclides and Isotopes | 核素与同位素

Isotopes are forms of the same element with the same proton number Z but different neutron numbers, and hence different nucleon

Published by TutorHao | A-Level Physics Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）