Why are nuclear fusion reactions predominant in the Universe, and not nuclear fission reactions?

The universe is composed primarily of light elements – hydrogen and helium. At high temperatures, they are synthesized into heavier elements. There are very few elements with a large mass number, with which fission reactions can occur, in the Universe.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.