Elements consist of atoms that consist of a nucleus of positive protons, neutral neutrons, and a shell of electrons. 组成元素的原子是由带正电的质子,中性的中子组成的原子核以及核外电子构成的。
Alpha particles are positively charged helium nuclei obtained from natural radioactive decay. 粒子是从天然放射性蜕变得到的带正电的氦核。