Protons, Electrons, and the Periodic Table | 质子、电子与元素周期表

📚 Protons, Electrons, and the Periodic Table | 质子、电子与元素周期表

Atoms are the building blocks of all matter. To understand the periodic table, you first need to know about three subatomic particles: protons, neutrons and electrons. Protons give an element its identity, electrons control its chemical reactions, and the periodic table organises all known elements by the number of protons.

原子是所有物质的基本构成单元。要理解元素周期表，首先需要认识三种亚原子粒子：质子、中子和电子。质子决定元素的身份，电子控制元素的化学反应，而元素周期表则按照质子数将所有已知元素系统地排列起来。

1. The Atom at a Glance | 原子速览

An atom is the smallest neutral particle of an element that can take part in chemical reactions. It contains a tiny, dense central nucleus made of protons and neutrons. Around the nucleus, electrons move in regions called shells or energy levels. Protons carry a positive charge, electrons carry a negative charge, and neutrons have no charge.

原子是元素能够参与化学反应的最小中性粒子。它含有一个微小而致密的中心原子核，核内由质子和中子组成。在原子核周围，电子在被称为电子层或能级的区域内运动。质子带正电荷，电子带负电荷，中子不带电荷。

Because the charges on protons and electrons are equal but opposite, a neutral atom has the same number of protons and electrons. The overall charge is therefore zero. This balance is central to understanding how atoms become ions later.

由于质子和电子所带电荷大小相等、符号相反，中性原子的质子数和电子数相同，因此总电荷为零。这种电荷平衡对以后理解原子如何变成离子至关重要。

2. Relative Mass and Charge of Subatomic Particles | 亚原子粒子的相对质量与电荷

Scientists use relative mass and relative charge to compare subatomic particles easily. A proton is given a relative mass of 1 and a relative charge of +1. A neutron also has a relative mass of 1 but a relative charge of 0. An electron has a relative charge of -1 and a very small relative mass, often treated as 0 at KS3 level.

科学家使用相对质量和相对电荷来方便地比较亚原子粒子。质子的相对质量定为1，相对电荷为+1。中子的相对质量也是1，但相对电荷为0。电子的相对电荷为-1，相对质量非常小，在KS3阶段通常视为0。