084 原子是空的空間嗎?
Is an atom an empty space?
（https://www.nuclear-power.com/）
原子是空的空間嗎?
氦-4原子與灰色陰影中的電子雲的形象描繪。質子和中子最有可能在同一空間，即在中心點被發現
來源:wikipedia.org License CC BY-SA 3.0
The volume of an atom is about 15 orders of magnitude larger than the volume of a nucleus. For uranium atom, the Van der Waals radius is about 186 pm = 1.86 ×10−10 m. The Van der Waals radius, rw, of an atom is the radius of an imaginary hard-sphere representing the distance of closest approach for another atom. The uranium atom has a volume of about 26.9 ×10−30 m3, assuming a spherical shape. But this “huge” space is occupied primarily by electrons because the nucleus occupies only about 1721×10−45 m3 of space. These electrons together weigh only a fraction (let say 0.05%) of the entire atom.
原子的體積大約比原子核的體積大15個數量級。鈾原子的範德華半徑約為186 pm = 1.86 ×10^−10 m。一個原子的範德華半徑rw是一個假想的硬球的半徑，它表示最接近另一個原子的距離。鈾原子的體積約為26.9 ×10^−30 m^3，假定為球形。但這個“巨大”的空間主要由電子佔據，因為原子核只佔大約1721×10 ^- 45 m^3的空間。這些電子加在一起只佔整個原子的一小部分（比如說0.05%）。
It may seem that the space and the matter are empty, but it is not. Due to the quantum nature of electrons, the electrons are not pointing particles, and they are smeared out over the whole atom. The classical description cannot be used to describe things on the atomic scale. On the atomic scale, physicists have found that quantum mechanics describes things very well on that scale. Particle locations in quantum mechanics are not at an exact position. A probability density function describes them. Therefore the space in an atom (between electrons and an atomic nucleus) is not empty. Still, it is filled by a probability density function of electrons (usually known as “electron cloud”).
似乎看起來空間和物質是空的，但並非如此。由於電子的量子性質，電子並不是指向粒子的，它們似被塗抹在整個原子上。經典描述不能用來描述原子尺度上的事物。在原子尺度上，物理學家發現量子力學可以很好地描述原子尺度上的事物。量子力學中粒子的位置並不是一個精確的位置。一個機率密度函式對其進行了描述。因此，原子的空間（電子和原子核之間）不是空的。儘管如此，它還是被電子的機率密度函式（通常被稱為“電子雲”）所填充。
(待續)
