Briefly explain why radiation was trapped for 380,000 years ...

[vHAUNG6011]

Briefly explain why radiation was trapped for 380,000 years during the era of nuclei, and why the cosmic background radiation was formed at the end of this era.
 
  What will be an ideal response?

Question 2

Without greenhouse gases, Earth's surface would be frozen over.
 
  Indicate whether the statement is true or false

[Meganchabluk]

Answer to Question 1

During the era of nuclei, the universe consisted of a hot plasma of hydrogen nuclei, helium nuclei, and free electrons. Throughout this era, photons bounced rapidly from one electron to the next, just as they do deep inside the Sun today, never managing to travel far between collisions. If a nucleus managed to capture an electron to form a neutral atom, one of the photons quickly ionized it. This era came to an end when the expanding universe had cooled down to about 3,000 K. At this temperature, the hydrogen and helium nuclei were able to capture electrons and form stable, neutral atoms for the first time. With all electrons bound into atoms, the photons were, for the first time, able to stream freely across the universe. It is this radiation that forms the cosmic microwave background radiation.

Answer to Question 2

TRUE

[vHAUNG6011]

TY

[Meganchabluk]

You're welcome