About how hot was the Big Bang when matter and energy "decoupled"?

Question

Quizplus · Accepted Answer

At the time of decoupling, the Universe was about 380,000 years old and had cooled to a temperature of around 3,000 Kelvin (K). The decoupling of matter and energy happened about 380,000 years after the Big Bang and at a temperature of around 3,000 K. This is when the universe became transparent as photons were able to travel freely without interacting with charged particles. This event is also what allows us to observe the Cosmic Microwave Background Radiation today.

About How Hot Was the Big Bang When Matter and Energy