The period of time before the formation of atoms and protons in the universe is often referred to as the "cosmic dark ages." It is a period of time between the Big Bang, which marks the beginning of the universe, and the formation of the first stable atoms.
The cosmic dark ages lasted approximately 380,000 years after the Big Bang. During this time, the universe was a hot, dense plasma consisting mainly of protons, electrons, and photons. The high energy and density prevented electrons and protons from combining to form stable atoms.
It was only when the universe cooled down sufficiently, around 380,000 years after the Big Bang, that the protons and electrons could combine to form neutral hydrogen atoms through a process called recombination. This event marked the end of the cosmic dark ages and the beginning of the era of transparent universe, as the photons could then travel freely through space without being continuously scattered by charged particles.
It's important to note that prior to the formation of atoms and protons, the universe was in a highly energetic and rapidly expanding state. Our understanding of the early universe and its evolution is based on the observations and theories derived from cosmology and astrophysics.