We perceive a world of great diversity but numerous things are composed of about a hundred different chemical elements, among them are hydrogen, carbon, nitrogen, oxygen, iron, and uranium. These elements are combined with one another in a multitude of ways to produce complexity of all objects. However, there are only three nucleosynthetic astrophysical sites: (i) big bang nucleosynthesis, where hydrogen and helium are produced; (ii) stars, where all elements from carbon to uranium are synthesized and (iii) interstellar medium in galaxies where lithium (a part of), beryllium and boron are made by non-thermal collisions between cosmic rays and interstellar matter. The origin of the atoms is now well understood. It is one of the greatest astrophysical discovery in the twentieth century. All the elements in the Mendeleev table, and specifically the atoms of life: carbon, nitrogen and oxygen, come from the work of all generations of stars in galaxies. Presently, after 13.8 Gyr, atomic matter in the universe is composed of 70% hydrogen, 28% helium and only about 2% by mass, of all the other elements. Complex (and also some specific light) atoms are rare in the Universe.

我们认为世界是一个多元化的世界，但是许多事物由大约一百种不同的化学元素组成，其中包括氢，碳，氮，氧，铁和铀。这些元素以多种方式相互组合以产生所有对象的复杂性。但是，只有三个核合成天体物理位点：（i）大爆炸核合成，产生氢和氦；（ii）合成碳和铀的所有元素的恒星，以及（iii）星系中的星际介质，其中锂（一部分），铍和硼是由宇宙射线与星际物质之间的非热碰撞产生的。现在已经很好地了解了原子的起源。这是二十世纪最伟大的天体物理学发现之一。门捷列夫表中的所有元素，特别是生命的原子：碳，氮和氧来自星系中所有世代恒星的工作。目前，在13.8 Gyr之后，宇宙中的原子物质由所有其他元素中的70％氢，28％氦和仅约2％的质量组成。复杂原子（还有一些特定的光）在宇宙中很少见。